Mineralogy Summary PDF

Mineralogy The study of minerals is called Mineralogy. It includes : 1. Chemistry of minerals 2. Crystal structure 3. Physical properties of mineral 4. origin of minerals 5. Classification of minerals 6. Their geographical distribution 7. Their utili...

Mineralogy The study of minerals is called Mineralogy. It includes : 1. Chemistry of minerals 2. Crystal structure 3. Physical properties of mineral 4. origin of minerals 5. Classification of minerals 6. Their geographical distribution 7. Their utilization There are about 5,400 minerals known by the International Mineralogical Association (IMA). Some are rare and precious such as gold & diamond, while others are more common, such as quartz. The silicate minerals compose over 90% of the Earth's crust. Examples Of Silicate Minerals : Orthoclase KAlSi3O8 , Albite NaAlSi3O8 , Quartz SiO2 , Zircon ZrSiO4 Kaolinite Al2Si2O5(OH)4 → (a layered silicate mineral) , Talc Mg3Si4O10(OH)2 → (the softest mineral) ⇢ Almost 99% of the minerals making up the Earth’s crust are made up of just 8 elements. What is a Mineral? It's a naturally occurring homogeneous solid with a definite chemical composition & an ordered atomic arrangement. It's formed by inorganic processes. A mineral is different from a rock, which can be an aggregate of minerals or non-minerals and doesn't have one specific chemical composition, as a mineral does. What do all minerals have in common? It must occur naturally. It is inorganic not resulting from the activity of living organisms. It must be a solid. It must possess an orderly internal structure (its atoms must be arranged in a geometric pattern). It must have a definite chemical. " Minerals are naturally occurring " It must have been formed by natural geologic processes. The products of industrial or commercial processes aren't considered true minerals. This means man-made substances such as steel or cement or glass aren't minerals. " Minerals are solid substances " Minerals are solid within the normal temperature ranges of the earth’s surface. A mineral isn't a gas, or a liquid. Petroleum is not a mineral. " Minerals are homogeneous " Homogeneous means that it is a compound that contains the same chemical composition throughout the mineral, & can't by physically separated into more than one chemical compound  " Ordered atomic arrangement " It means that the atoms in a mineral are arranged in geometric pattern. This ordered arrangement of atoms is called a crystal structure, and thus all minerals are crystalline. EX: Halite (salt) : It's made up of an equal number of atoms of sodium & chlorine. (4 Cl atoms & 4 Na atoms). ⇢ Diamond and Halite have the same composition. Structure of diamond : Each carbon atom in diamond is held in place by 4 strong covalent bonds. These bonds require significant amounts of energy to break. This means that they have a high melting point of 3750 °C. Structure of graphite : The carbon atoms in graphite are arranged in layers; within each layer there are strong covalent bonds – this means that it has a high melting point. Between layers there are much weaker forces – this means that they are soft and slippery and can slide over each other; this is what allows us to write with a pencil. Between the layers the electrons are delocalized (they can move freely & gain a charge) meaning that they can conduct electricity. " Minerals usually formed by an inorganic process " Mineral has been formed as a result of geological processes. In addition, biogenic substances were excluded. Biogenic substances are chemical compounds produced entirely by biological processes. → PEARL is considered a gemstone, although it isn't a mineral. It's a composite of the mineral Aragonite (CaCO3) & the organic compound Conchiolin (a protein). " A mineral must have a definite chemical composition " The chemical variation is associated with the replacement of the cations within the mineral. Most minerals don't have such well-defined compositions. → Dolomite, CaMg(CO3)2, isn't always a pure Ca-Mg-carbonate. It may contain amounts of Fe and Mn in place of Mg. → The composition of dolomite is said to range between certain limits & isn't fixed. Ca(Mg,Fe,Mn)(CO3)2. " What is definite chemical composition? " A mineral must be expressed by a specific chemical formula. For example, the chemical composition of quartz is SiO2 (contains no chemical elements other than silicon and oxygen ) Polymorph It's the ability of a specific chemical composition to crystallize in more than one form. Diamond & Graphite, which are two different minerals composed of the same substance. The Al2SiO5 polymorphs : Andalusite , Sillimanite , Kyanite. Calcite mineral & Aragonite mineral are polymorphs. Mineraloid A Mineraloid is a naturally occurring, inorganic solid that doesn't exhibit crystallinity. It may have the outward appearance of a mineral, but it doesn't have the “ordered atomic structure”. Some mineraloids also lack the “definite chemical composition. Common mineraloids : Amber : It's the organic fossil of tree , non-crystalline. Obsidian : volcanic (amorphous) glass , non-crystalline. Jet : (It's a type of lignite , a precursor to coal) , organic , non-crystalline. Opal : It's an amorphous silica (internal atomic structure isn't ordered) , with a chemical composition of SiO2.nH2O. Economic Importance of Minerals : Copper: electric cables, wires, switches. Feldspar: Glass, Ceramics, Sanitary ware. Calcite: Toothpaste, Construction, Antacid tablets. Iron: buildings, magnets, cars. Halite: table salt, food preservation. Graphite: electrical uses , a pencil , a lubricant due to its slippery nature. Minerals are divided in two broad groups : 1. Rock forming minerals 2. Ore forming minerals Rock forming minerals : are found in abundance in different types of rocks, they're divided into 2 groups : 1. Primary minerals : Those which are crystallized directly from magma or lava. They're divided into 2 groups : Essential minerals B. Accessory minerals A) Essential minerals: have been used in the definition of the rock. Ex: Granite rock (consists of feldspar) , quartz , biotite. B) Accessory mineral: whose presence or absence doesn't change the definition of rock. Ex: Zircon, Sphene and Apatite in granitic rocks. Note : Apatite is the world's major source of phosphorus. 2. Secondary minerals : They're formed by the alteration of the primary minerals. They are formed through weathering and hydrothermal alteration. Ex: Clay Minerals Ore forming minerals : Certain kinds of mineral can be treated for metal extraction more easily than others ; these are commonly referred to as ore mineral. Hematite (Fe2O3) : an iron-ore mineral. Galena (PbS) : a lead-ore mineral. Malachite (Cu2(CO3)(OH)2) : a copper-ore mineral. Au : native gold Factors affecting ore minerals → 2 factors determine whether a given mineral is suitable to be an ore mineral. The 1st : the ease with which a mineral can be separated from the gangue and concen trated for smelting. The 2nd : smelting which, releasing the metal from the other elements to which it is chemically bonded in the mineral. → The suitability of an ore mineral : ֍ It's the amount of energy needed to break the chemical bonds & release the metal from this mineral. → Less energy is needed to smelt sulfide, oxide, or hydroxide minerals than is required to smelt a silicate mineral. → The sulfides are the most important group of ore minerals. Felsic & Mafic minerals Mafic minerals are enriched in Iron and Magnesium. Light colored are called Felsic group , Ex: Quartz , Feldspar. Dark colored are called Mafic group , Ex: Olivine , Pyroxene , Amphibole , Biotite (dark mica). Gangue mineral There is always an abundance of worthless minerals associated with the ore minerals. These are called gangue. Metallic minerals They're the source of metals , Ex: iron , aluminum , copper , zinc , manganese , lead , chrome , platinum. Industrial Minerals They're mined for their characteristic physical properties (hardness , color , luster). The most important application of industrial minerals : Abrasives : Garnet , Corundum. Cosmetics , paper , rubber : Calcite , Talc. Brick-making , ceramic , raw material : Feldspar , Talc , Kaolinite. Agricultural industry : Phosphates , agricultural lime dolomite , Micas , gypsum.  Naming Of Minerals Minerals are given names on the basis of : physical property chemical aspect locality mineralogist. Albite (NaAlSi3O8) Latin word → albus (white), in allusion to its color. Chromite (FeCr2O4) it has amounts of chromium. Magnetite (Fe3O4) it has magnetic properties. Franklinite (ZnFe2O4) : in Franklin, New Jersey. Sillimanite (Al2SiO5) : Professor / Benjamin Silliman. Identification Of Minerals The minerals are identified by their physical properties (color, luster, crystal form, hardness) by the naked eye or with a hand-lens. Or by the optical properties in the reflected light microscope or transmitted light microscope of polished & thin sections. Mineral identification can also be done by : X-Ray diffractometry (XRD) & Chemical Analysis in the Electron Microprobe. Minerals can be identified by physical properties : Crystal habit Cleavage Fracture Quartz : has a conchoidal fracture. Mica : has a single, perfect cleavage. Equant garnet : same dimension in all directions. Crystal Habit Habit is the characteristic external shape of an individual crystal or groups of crystals. Crystal faces are well-developed is Euhedral. Crystal with partially developed faces is Subhedral. Crystal with undeveloped crystal faces is Anhedral. Acicular : a crystal habit composed of a radiating mass of slender , needle-like crystals. Ex: gypsum & Natrolite (Na2Al2Si3O10.2H2O) Drusy : a coating of fine crystals on a rock fracture surface, vein or within a vug. Geode habit : Open cores, lined with different minerals. (Hollow cavities, lined with crystals). Ex: quartz & calcite. Stalactitic : (cone shape) Ex: Calcite. Fibrous : Extremely slender prisms. Ex: serpentine groups. Botryoidal or globular : Grape-like, hemispherical masses. Ex: Malachite & Hematite. Foliated or micaceous or lamellar (layered) : Layered structure , parting into thin sheets. Ex: muscovite. (Mica). Equant habits (width, length and breadth are equal) Rosette habit : Radiating rose like aggregates. Ex: Barite Massive habit : Shapeless , no distinct external crystal shape. Ex: Ilmenite Dendritic : Tree-like , branching in one or more direction from central point. Ex: Pyrolusite Columnar habit : Similar to fibrous , long , slender prism often parallel growth. Ex: Gypsum Pseudomorphism (false shape) Some minerals may replace other existing minerals while preserving the original's habit. Find the scientific term : A mineral that replaces another mineral's chemistry with its own without changing the outward shape of the original mineral. Answer : Pseudomorph. Types of Gypsum Selenite : Transparent & bladed crystals of gypsum. Satin spar (CaSO4.2H2O) : Pearly, fibrous masses of gypsum. Alabaster : massive fine-grained, white or lightly tinted variety of gypsum. ⇢ The mineral’s color results from combination of the light wavelengths reached eyes. Idiochromatic Minerals Some minerals are always the same color. Color of these minerals is derived from the presence of one or more elements in their crystal lattice ( chemical composition). Ex: Cu in azurite, Cu3(CO3)(OH) (blue). Find scientific term : all specimens of the mineral are the same color. Answer : Idiochromatic mineral. (because it has essential elements in it) Chromophores & Allochromatic Minerals Ions of certain elements are highly absorptive of selected wavelengths of light. They possess strong pigmenting capabilities. These chromophore (color causing elements) Ex : Fe, Cr, Co, Ni, V, Mn, Cu. Find the scientific term : Color of minerals due to the presence of impurities. Answer : Allochromatic minerals. Examples 1. Impurities of Chromium (Cr) in beryl are responsible for the deep green of Emerald (Be3Al2Si6O18) or Aquamarine. 2. If Corundum contains Chromium (Cr), it becomes Red Gem called : Ruby If Corundum contains (Fe or Ti), it becomes Blue Gem called : Sapphire 3. The Violet (purple) color of amethyst is due to presence of (Fe) in Quartz. 4. The Rose color of rose quartz is due to presence of Titanium (Ti). 5. Smoky Quartz result from Radioactivity. 6. Pure Quartz is colorless. Color of mineral : It's the most easily observed property, but usually the least useful and little used in identification. Why : The mineral's color isn't a very good property to use to identify minerals ? Answer : Because many minerals may have chemical impurities exposure to heat , moisture , air. Play of Colors (Iridescence) It results from diffracted & reflected light from closely spaced fractures, cleavage planes, exsolution, or minute inclusions in parallel orientation Complete : Play of color in Opal is due to ……. Answer : interference & diffraction light from submicroscopic layers. Play of color in Labradorite is due to ……. Answer : reflected light from exsolution laminae. Chatoyancy ( cat's eye effect ) It's an optical reflectance effect seen in certain gemstones & give silky or wavy appearance in minerals caused by closely packed parallel fibers of inclusions. The best-known gem materials that exhibit this phenomenon are : 1. "Satin Spar" gypsum. 2. "Tiger’s Eye" (fibrous crocidolite replaced by Quartz). 3. Cat’s eye (Chrysoberyl)(BeAl2O4). Find name of mineral : Mineral shows a chatoyancy feature. Answer : Satin spar (a fibrous variety of gypsum) or Chrysoberyl. Tiger's eye quartz It's a pseudomorph of compact Quartz after the fibrous mineral Crocidolite. Fibrous form of the amphibole mineral. Inclusions which cause the stars are orientated parallel to crystal faces Asterism Satin Spar. Asterism It's a type of chatoyancy in which fibers or inclusions reflecting light, are arranged in a pattern radiating outwards from a point producing a star-like pattern. Ex : Rubies, Sapphires, Phlogopite Mica. Transparency (Ability of a mineral to transmit light) According to transparency, minerals are classified into : Transparent (light pass through mineral & images seen clearly). Translucent (light passes through mineral but is diffused so that images can't be seen clearly ). Opaque (no light passes through mineral). Luminescence Mineral glows under ultraviolet light as result of absorption of photons ( electromagnetic radiation). Fluorite. Glowing of mineral is caused by presence of impurities (activators) in a mineral. Luminescence (Photoluminescence) : is the emission of light by a mineral due to reaction with ultraviolet light X-rays. Types of luminescence : Fluorescence & Phosphorescence. Fluorescence & Phosphorescence ⇢ Fluorescence : It results from electrons orbiting mineral’s atoms being excited by ultraviolet light , electrons absorb energy & jump to higher orbits, then fall back to original orbits giving visible light ⇢ Phosphorescence : It's the same thing, but continues for a time after the source of excitation is removed , giving energy as visible light more slowly. The fact is that most fluorescent minerals show phosphorescence to some extent. UV is a form of Electromagnetic Radiation invisible to human eye. 1. Willemite → Luminescence. 2. Magnetite → magnetism. 3. Labradorite → play of color (Iridescence) 4. Amethyst → purple color (Allochromatic mineral). Thermoluminescence It's a form of luminescence exhibited by some minerals, when absorbed energy from electromagnetic radiation or other ionizing radiation is reemitted as light when heating mineral. The emission of light through fluorescence process is nearly simultaneous with absorption of excitation light when emission persists longer after excitation light has been extinguished, this is referred to as phosphorescence. Most of manganiferous calcite fluoresces in various tones of Red to Pale Pink. Pure Calcite is Negative. Streak It's the color of the mineral in powdered form. (It shows true color of mineral). In large solid form, trace elements can change color appearance of a mineral by reflecting light in a certain way. Streak of metallic & non-metallic minerals : Streak of metallic minerals appears dark because small particles of these minerals absorb light hitting them. Non-metallic minerals appear lighter in color or almost white because they reflect most of the light. Trace amounts of impurities don't tend to affect streak of a mineral, so this characteristic is more predictable than color. 2 different specimens of same mineral possess same streak, whereas they may display different colors. Streak is a more reliable property than color ; because streak is a more accurate illustration of the mineral’s color. Streak Plate : A specimen of the mineral is placed against a piece of unglazed porcelain plate. Luster It's the general appearance of the mineral’s surface in reflected light. Metallic luster (shiny) : minerals are opaque & give a prominent black or dark streak & are dense. Ex : Galena. Submetallic luster : mineral is opaque & dull. The mineral is dark colored. Nonmetallic Luster : mineral is translucent (transparent) & has light streak (colorless). Some specific types of non-metallic lusters : 1. Waxy : like wax. Ex: Sulfur. 2. Vitreous : resembles glass. Ex: Quartz. 3. Resinous : resembles a resin. Ex: Sphalerite. 4. Pearly : pearl-like. Ex: Talc. 5. Greasy : covered by oil or grease. Ex: Graphite. 6. Silky : like silk. Ex: Satin Spar. Adamantine : brilliant. Ex: Diamond. 8. Dull (Earthy) : minerals reflect light very poorly & don't shine. Ex: Kaolinite.  Cohesive Properties 1. Hardness It's the resistance of mineral to scratching & determined by scratching mineral with known hardness mineral. It's determined on the basis of Moh’s relative scale of hardness exhibited by (10) common minerals. Hardness of a mineral can differ slightly in direction of scratching & may vary with direction within the same grain. Minerals with covalent bonds are hardest & minerals with ionic, metallic ,or van der Waals bonding are softer. 2. Tenacity It's the resistance of a mineral to breaking , crushing or bending. It can be described by the following terms : 1. Brittle : if mineral powders easily (halite , calcite , pyrite). 2. Malleable : if mineral hammered into sheets (gold , copper). 3. Sectile : if a mineral cut into thin shavings with knife (gypsum , Talc). 4. Ductile : if a mineral drawn into wire (gold , copper) 5. Flexible : if mineral is bent but doesn't resume original shape (chlorite). 6. Elastic : if a mineral bends & resumes original shape (mica). Differences in hardness between minerals are caused by internal arrangement of atoms. 3. Cleavage It's the tendency of a mineral to split along one or more smooth flat planes or surfaces. Crystals often contain planes of weakness along which the bonding between atoms is weaker than along other planes. In such a case, if mineral is struck with a hard object, it will tend to break along these planes. ⇢ It may be one to multi-directional. 1. Perfect : if it cleaves along perfect planes. 2. Good : if cleavage is produced with difficulty but has obvious cleavage planes. 3. Fair (Poor) : (if it cleaves along poorly defined planes). Right or Wrong : 1. The same cleavage quality & quantity will be present in all specimens of the same mineral. (✔) 2. Micas have 1 direction of cleavage. (✔) Pyroxene and amphibole aren't polymorphs. (✔) All minerals display a physical property known as fracture. (✔) All minerals have cleavage. (✘) Calcite has 3 directions of cleavage (rhombohedral). (✔) Halite has cubic cleavage. (✔) Mica(Muscovite) has basal cleavage. (✔) Muscovite : It has a single perfect cleavage, flaky nature. The yellow stars are on parallel cleavage faces that all represent the same cleavage direction. Quartz : It has no cleavages, but exhibits distinctive conchoidal fracture. 4. Fracture If the mineral contains no planes of weakness, it will break along random directions called fracture. Kinds of fracture : Conchoidal fracture : breaks along smooth curved surfaces. Fibrous and splintery : similar to the way wood breaks. Hackly-jagged : fractures with sharp edges. Uneven (Irregular) : rough irregular surfaces. Comparison between cleavage, parting and fracture : Cleavage : minerals break along smooth, flat surfaces & every fragment has the same shape. Parting : minerals break along planes that are weakened by applied force. Fracture : minerals break randomly with rough or jagged edge. Piezoelectricity It means electricity resulting from pressure. Ex: Quartz , Tourmaline , Topaz. A piezoelectric disk generates a voltage when deformed (change in shape). (Electric Property) : A flow of electrons in mineral crystals by exerting compressive pressure at both ends of "c" axis of crystals which have no center of symmetry. The piezoelectric materials used for converting energy are called as Transducer Pyroelectricity (electric property) It's the ability of material to generate a temporary voltage (when heated). The change in temperature modifies positions of atoms , such that the polarization of the material changes. Pyroelectric Crystals don't have center of symmetry. Uses of Piezoelectricity : Piezoelectric igniters used for Butane Lighters , Gas Stoves , Electricity Generation , Electronic Devices. Magnetism It's the characteristic property that allows a mineral to attract or repel other magnetic materials. Diamagnetic materials : repel from magnetic field. Ex : Calcite , have a weak -ve susceptibility to magnetic field. They include most elements in periodic table : Bismuth, Copper, Silver, Gold. Paramagnetic materials : weak attraction to magnetic field. Ex : Ilmenite , have a small +ve susceptibility to magnetic field. They include : Ilmenite, Magnesium, Molybdenum, Lithium, Tantalum. Ferromagnetic materials : Ex : Magnetite have a large +ve susceptibility to an external magnetic field. They include : Iron , Gadolinium , Dysprosium. Uses : Electromagnets , Electric Motors , Generators , Transformers , Magnetic Storage (Ex : tape recorders & hard disks). Chromite (weakly) Columbite (weakly) Iron-nickel (attracted to magnets) Platinum (weakly) Tantalite (weakly) Ilmenite (weakly, when heated) Siderite (weakly when heated) Magnetite (strongly) Pyrrhotite (strongly, but is inconsistent) Sense Properties Odor (Smell) : → Most minerals have no odor if they aren't moistened, heated, breathed upon, or rubbed. → Some minerals have a distinctive smell. Ex: Sulfur (smells like Rotten-Eggs). Taste : Only soluble minerals have a taste. Ex: Halite. Sulfur gives a mild odor resembling a smell of a lighting match. If heated or struck, it gives a rotten-egg odor. Sulfides (Pyrite) gives a rotten-egg odor if heated or struck. Native Arsenic gives a very mild garlic smell, if heated or struck, it gives a powerful garlic-odor. Arsenopyrite contains arsenic. If heated or struck, give a garlic-odor. Kaolinite gives a fresh-clay odor. Epsomite : MgSO4.7H2O (bitter) Glauberite : Na2Ca(SO4)2 (bitter salty) Halite : NaCl (salty) Sylvite : KCl (bitter)  Specific Gravity 𝑾𝒂 Specific gravity = W = weight , a = air , w = water 𝑾𝒂 − 𝑾𝒘 Most silicate, or rock forming, minerals have specific gravities ranges from 2.6 to 3.4 Minerals with a specific gravity under 2 are light , between 2 & 4.5 average & greater than 4.5 are heavy. Metallic ore minerals are usually heavier than silicate minerals , with specific gravities ranges from 5 to 8 Barite (non-metallic) has high & distinctive specific gravity. 2 different minerals may be same size , but their weight may be very different. What factors control the specific gravity of a mineral ? The specific gravity of a mineral depends on: 1. kind of atoms. 2. The manner in which atoms are packed together. 3. Impurities present in minerals. Both diamond & graphite have the same chemical formula (C) , but difference in S.G. Why : diamond's S.G. = 3.5 , while graphite is only 2.2 ? Answer : Because carbon atoms in diamond are more tightly packed than in graphite. Determination of specific gravity accurately, the mineral must be : 1. Pure.. Homogenous. 3. It must be compact with no cracks or cavities causing bubbles. There are four different methods of determining a specific gravity include : Jolly balance , Torsion balance , Pycnometer , Heavy Liquids. Heavy liquids : are solutions with high density & low viscosity, used for determination density & for separation mixtures. Ex: 1. Thoulets solution : A yellowish-green, transparent, solution of Potassium Mercuric Iodide , having (S.G.) = 3.19 2. Bromoform (CHBr3) : is a brominated organic, colorless liquid (soluble in acetone), (S.G.) = 2.890 The mineral olivine (Mg,Fe)2SiO4 , 1 Si & 4 O2 atoms are bonded with 2 atoms of either Mg or Fe. The comma between (Fe) and (Mg) shows that the 2 elements can occupy the same location in crystal structure & substitute for one another. → Qualitative Analysis : determine what elements are present. → Quantitative Analysis : determine how much elements are present. Acid Test means / Certain minerals will bubble when dilute hydrochloric acid is applied to surface. This is characteristic of minerals containing carbonate anion. 1. Magnesium Spinel MgAl2O4 2. Gahnite ZnAl2O4 (Zinc Spinel) 3. Hercynite FeAl2O4 (Iron Spinel) 4. Galaxite MnAl2O4 (Manganese Spinel) → The term "Acid Test" means placing a drop of dilute (5% : 10%) hydrochloric acid on a rock or mineral & watching for bubbles of CO2 gas to be released. → The bubbles show presence of carbonate minerals , Ex: Calcite , Dolomite. What are the most common qualitative analyses? 1. BEAD TEST (borax bead) / It's an analytical method used for identifying unknown metal. In this case, a mineral-coated bead is heated in a flame and cooled to observe its characteristic color. How to Do the Bead test : First make a clear bead by: fusing a small quantity of borax. (Na tetraborate: Na2B4O7.10H2O) or phosphorous salt (NaNH4HPO4 Ammonium sodium phosphate) , onto a loop of platinum wire in a Bunsen burner flame. After bead is formed, coat it with a dry sample of the unknown mineral to be tested & re-introduce the bead into flame. The inner cone of flame is the reducing flame , the outer portion is the oxidizing flame. 2. FLAME TEST / It's used to identity an unknown metal based on characteristic color the salt turns the flame of a Bunsen burner In this case, heat of the flame excites the electrons of the metal ions, causing them to emit visible color. Every element has a signature emission spectrum that used to differentiate between 1 element & another. Many elements produce colors in flame when heated. The origin of this phenomenon lies in the arrangement of the electrons in atoms of different elements. How to Do the Flame test : First, you need a clean wire loop. (Platinum or nickel-chromium loops are most common) They may be cleaned by dipping in hydrochloric or nitric acid, followed by rinsing with distilled water. The loop must be cleaned between tests & the clean loop is dipped in either a powder or solution of a metal. The loop with sample is placed in the clear or blue part of the flame and the resulting color is observed. The mineral is identified by comparing the observed flame color against known values from a table or chart. Carbonate minerals → They're the major constituents of sedimentary rocks. → They're found in igneous & metamorphic rocks, either as primary or as secondary minerals. → The identification & discrimination of carbonate minerals in hand specimens or thin sections, are made easier by use of simple chemical staining methods, without losing a great amount of time in chemical analyses or optical investigations. Discrimination of Rhodochrosite : (1) Benzidine test Discrimination between Magnesite & Smithsonite : (1) Friedman test , (2) Magneson test , (3) Tropaeolin. Discrimination between Ankerite & Siderite : (1) Kirchberg test , (2) Hydrogen peroxide-potassium hydroxide test. Discrimination between Aragonite & Calcite : (1) Meigen test , (2) Feigl test , (3) Rhodizonic acid test. Discrimination between Calcite & Dolomite : (1) Lemberg hydroxide test , (2) Lemberg test , (3) Fairbanks test , (4) Lemberg silver chromate test , (5) Copper nitrate test , (6) Trypan blue test , (7) Harris hematoxilin test , (8) Alizarin red test , (9) Friedman test , (10) Potassium ferricyanide test , (11) Alizarin red & potassium ferricyanide composite test , (12) Mann test , (13) Ramsden test. Meigen Test (discrimination between Aragonite & Calcite) Solution : Cobalt nitrate [CO(NO3)2.6H2O] Test : Specimen is boiled in Cobalt Nitrate solution for 20 minutes. Result : During test : aragonite first takes a lilac (violet) color, which slowly turns into purple. On other hand, in calcite : such coloring is either not present or slow developing. In the latter case, this color disappears within a few hours after test. ------------------------------------------------------------------------------------------------------------------------------------------------------ Copper Nitrate Test (discrimination between Calcite & Dolomite) Solution : Copper nitrate solution. Prepared by mixing 332 gm of Cu(NO3)2.6H2O & 1000 cc distilled water. In addition, there should be a sufficient amount of NH4OH (ammonium hydroxide) available. Test : → Specimen is soaked in copper nitrate solution for about 5-6 hours. → After treatment, the specimen is washed. dried and immersed in NH4OH solution for a few seconds. → Once again, the specimen is washed carefully. Result : Calcite acquires a green or bluish-green color, while dolomite doesn't show any change in color. ----------------------------------------------------------------------------------------------------------------------------------------------------- Lemberg test (discrimination between Calcite & Dolomite) Solution : 4 gm AlCl3 & 6 gm logwood chips are boiled in 60 cc distilled water for 20-25 min. After cooling, specimen is kept immersed in the solution for about 5-10 min. Result : During this time calcite acquires purple color as opposed to dolomite, which doesn't change color within first 20 minutes. However, after 20 minutes, dolomite turns into pale blue. ------------------------------------------------------------------------------------------------------------------------------------------------------  Types Of Chemical Analysis 1. Wet Chemical Analysis (wet chemistry involves dissolving a mineral in acid then analyzing solution). These analyses include : a) Gravimetric b) Volumetric c) Colorimetric 2. Spectroscopic Techniques : involve energy source that is used to bombard samples (electrons or neutrons can be excited) in order to produce electromagnetic signal that can be detected & analyzed. Spectroscopic Techniques Include : 1. Inductively coupled plasma mass spectrometer (ICP) (partially ionized plasma) 2. Atomic absorption analysis (AAS). 3. X-ray Fluorescence (XRF). 4. Scanning Electron Microscopy (SEM) performed on thin sections. 5. Electron-probe micro-analysis (EPMA) : Sample preparation for microprobe work requires a bit more effort. Thin sections must be made & ground to ~30μm thickness , then polished to a high gloss through a series (15‐20) steps. Samples must then be carbon coated and kept under vacuum before being qualitatively or quantitatively analyzed. 6. Neutron Activation analyses (NAA) : The different types of analysis are based on the half-lives of the elements of interest. All types of them are based on (any element can be made radioactive if it's bombarded with enough energy ). Gravimetric analysis : Quantitative analysis by weight. Colorimetric analysis : Quantitative chemical analysis by color using a colorimeter. Volumetric analysis : Quantitative analysis by the use of definite volumes of standard solutions or reagents. Determination of the volume of gases (changes in their volume) during combination. Borax Bead Test Borax bead is a mixture of NaBO2 and B2O3. B2O3 on heating combines readily with metal oxides such as Co , Ni , Cr , Cu , Mn to form the corresponding metaborates which possess characteristic colors. In oxidizing flame : 𝐁𝟐 𝐎𝟑 + 𝐂𝐮𝐒𝐎𝟒 → ⏟ 𝐂𝐮(𝐁𝐎𝟐 )𝟐 + 𝐒𝐎𝟑 𝐠𝐫𝐞𝐞𝐧 In reducing flame ∶ 𝟐𝐂𝐮(𝐁𝐎𝟐 )𝟐 + 𝐂 → ⏟ 𝟐𝐂𝐮𝐁𝐎𝟐 + 𝐁𝟐 𝐎𝟑 + 𝐂𝐎 𝐛𝐨𝐭𝐭𝐥𝐞 𝐠𝐫𝐞𝐞𝐧 𝟐𝐂𝐮𝐁𝐎𝟐 + 𝐂 → 𝟐𝐂𝐮 ⏟ + 𝐁𝟐 𝐎𝟑 + 𝐂𝐎 𝒓𝒆𝒅 Specific Gravity is determined by dividing the density of a material by the density of water at 4 ℃. For the calculation, the density of the material and that of the water must be expressed in the same units. Density of water = 1000 kilograms per cubic meter or 1 gram per cubic centimeter. Problem : Calculate the specific gravity of iron. The density of iron is 7850 kg/m³. Solution : The specific gravity of iron is 7.85  Radioactive atom emits energetic particles such as : Alpha particle , Beta particle , Gamma ray. Radioisotopes (Isotopes) are unstable & release radiation. Alpha decay involves ejection of a Helium Nucleus (2 protons and 2 neutrons) from the parent isotope. In Alpha Decay : Z decrease by 2 & A decrease by 4. Positron Emission involves ejection of Beta Plus particle. In Positron Emission : Z decrease by 1 & A remains the same. Half-Life : The time required for the amount of radioactive material to decrease by one-half. Half-lives for various radioisotopes can range from few microseconds to billions of years. Examples of radioactive minerals : Uraninite (Pitchblende) : an ore of Uranium. Monazite : a Phosphate mineral containing Thorium. Potassium (K) : isn't radioactive. → Quantitative Chemical Analysis of minerals is obtained by a variety of analytical techniques : X-ray fluorescence (XRF) Atomic Absorption Spectroscopy (AAS) Scanning Electron Microscopy (SEM) Summer Final 2020-2021 2023-2024  Summer 2021-2022 Final 2021-2022 Final 2022-2023 Alpha causes the least damage. Beta causes less damage. Gamma causes the most damage. t 1 t1⁄ Nt = No ( ) 2 2 No : the base carbon-14 amount at t = 0 Nt : the remaining quantity after time, t t1⁄ : "half-life" 2 t : the mean lifetime λ : the decay constant If an archaeologist found a fossil sample that contained 25% carbon-14 in comparison to a living sample, the time of the fossil sample's death could be determined by rearranging the above equation, since Nt , No and t1⁄ are known. 2 t N 25 1 t1⁄ t1⁄ ln( t ) 5730ln( ) 2 N o 100 Nt = No ( ) 2 → t = = = 11460 2 -ln(2) -0.693 This means that the fossil is 11460 years old. Endogenic Processes : deep-seated processes , proceed in the interior of earth & associated with igneous activity. Ex : Magmatic processes , Pegmatitic processes , Pneumatolytic processes , Hydrothermal processes , Metamorphism. Exogenic Processes : occur at the Earth's surface. Ex : Weathering (transporting & deposition) , Biogenic Processes. Weathering Types : 1. Chemical Weathering 2. Physical (Mechanical) Weathering 3. Biological Weathering Weathering Agents : water (rainfall) , wind , oxygen , CO2 , temperature , activity of living organisms. → Chemical Weathering : Decomposition of rock With change in chemical composition. Ex: Hydrolysis : reaction with water. Oxidation : reaction with oxygen (rock rusts). Dissolution : rock is completely dissolved. Carbonation : reaction with carbonic acid. → Mechanical Weathering : Disintegration of rock Without change in chemical composition. In presence of Carbonic Acid, Feldspar is altered by hydrolysis to Clay. Pyrite : is oxidized to Goethite. Calcite : will dissolve in weak acid, to calcium & bicarbonate. Bauxite Al(OH)3 : an ore aluminum, formed by chemical Weathering. Clay minerals & Oxide Minerals (Goethite , Hematite , Bauxite) are the most common products of chemical weathering. Quartz , Clay , Bauxite. Olivine , Ca-Plagioclase , Pyroxene , Amphibole. Olivine is a solid solution series mineral whose two most common end members are Forsterite and Fayalite. Factors affect the mineral products of Weathering : Resistance of primary minerals to chemical weathering. Climate. Evaporates They're formed by evaporation of lake water or seawater. The most important salts that precipitate from seawater : Halite , Gypsum , Calcite , Dolomite , Carnallite , Sylvite. Crystallization of Magma begins with minerals having High S.G. Olivine : crystallizes between 1200 and 1300 °C. Quartz : can crystallize at temperatures under 870 °C. Kimberlite : an igneous rock, contains diamonds. Pegmatite processes (700 – 400 °C) : → An coarse-grained igneous rock, formed underground when magma cools very slowly, with interlocking crystals usually larger than 2.5 cm. → Most pegmatites composed of Quartz, Feldspar & Mica , have a similar composition as granite.  Pneumatolysis (300 – 500 °C) Pneumatolysis : It's a process of mineral formation from the gaseous phase. ֍ All igneous magmas contain dissolved gases (water, carbonic acid, hydrogen sulfide, chlorine, fluorine, boric acid ). ֍ Magmatic vapor, gas and fluids of low density can transport metals. Hydrothermal process (50 – 400 °C) Hydrothermal waters are hot water solutions separating from magma. Hydrothermal solutions dissolve metallic elements from a large area & then precipitate ore minerals as molybdenite, gold-silver-barite-quartz, commonly along rock fractures and faults. Which of the following is not an essential condition for hydrothermal deposits ? A) Highly active fluids B) Highly enriched fluids C) Highly inactive fluids D) Suitable pathways Metamorphism It occurs deep in the earth under very high temperature & pressure. The most common metamorphic minerals : Garnet-Sepentine. Graphite occurs in metamorphic rocks formed from regional metamorphism or contact metamorphism of organic rich sedimentary rocks. Under high pressures & temperatures , graphite converts to diamond. Metamorphic processes : 1. Contact metamorphism (high temperature & low pressure) : rock minerals are changed by heat due to contact with magma. 2. Regional metamorphism (high temperature & High pressure) : rock minerals are changed by heat & pressure on wide region. Dynamic metamorphism : results from mechanical deformation. In what plate tectonic setting does regional metamorphism usually take place ? (1) Convergent plate boundaries (2) Divergent plate boundaries (3) Transform plate boundaries (4) Plate interiors Minerals have been classified on the basis of their chemical composition. Ex: halides, oxides, sulfates, carbonates, sulphides. Silicate Minerals are the most common of Earth's minerals Ex: Quartz, Feldspar, Mica, Amphibole, Pyroxene, Olivine. The base of unit of a silicate mineral is the (SiO4)4- (tetrahedron). Silicon & oxygen bond covalently to create a silicate tetrahedron (SiO4)4- , which is a four-sided pyramid shape with oxygen at each corner & silicon in the middle. The building block of the silicate minerals is the silica tetrahedron , represented by the following (SiO4)4-. Silicate Minerals are classified into 7 major sub-groups according to the structure of their silicate anion : 1. Nesosilicates (Orthosilicate) , Ex: Olivine (Mg2SiO4) → Independent tetrahedra : tetrahedra don't share any O2 atoms. Structure = Isolated Silicon Tetrahedral Chemical formula = [SiO4]4- 2. Sorosilicates Ex: Epidote Structure = Double Tetrahedra Chemical formula = [Si2O7]6- 3. Cyclosilicates Ex: Tourmaline Structure = Rings Chemical formula = [SinO3n]2n- 4. Inosilicates Ex: Pyroxene Structure = Single Chain Chemical formula = [SinO3n]2n- 5. Inosilicates Ex: Amphibole Structure = Double Chain Chemical formula = [Si4nO11n]6n- 6. Phyllosilicates Ex: Mica (Muscovite) Structure = Sheet Chemical formula = [Si2nO5n]2n- 7. Tectosilicates Ex: Feldspar , Quartz Structure = 3D framework Chemical formula = [AlxSiyO(2x+2y)]x-  Summer 1. The hardness of a mineral is most closely related to the : 2020-2021 (1) mineral's color (2) mineral's abundance in nature (3) amount of silica the mineral contains (4) internal arrangement of the mineral's atoms 2. What is the best way to determine if a mineral sample is calcite or quartz ? (1) Observe the color of the mineral. (2) Place the mineral near a magnetic compass. (3) Place a drop of acid on the mineral. (4) Measure the mass of the mineral. 3. Which physical property of this mineral is most easily seen in the photograph ? (1) Hardness (2) Cleavage (3) Streak (4) Luster 4. Most gypsum is formed by : (1) Heating of previously granitic rock. (2) Solidification of lava. (3) Compaction of organic remains. (4) Chemical deposition from seawater. 5. Which of the following is not true about a mineral ? (1) Naturally occurring. (2) Inorganic substance. (3) Organic substance. (4) Definite chemical composition. 6. The type of mineral showing variable color is : (1) Idiochromatic (2) Allochromatic (3) Iridescence (4) Fluorescence. 7. The chemical formula for olivine is (Mg,Fe)2SiO4, which means that in addition to silica, …………………. (1) magnesium and iron can substitute for one another (2) all olivine contains both magnesium and iron (3) magnesium is more common than iron (4) magnesium is heavier than iron 8. Calcite and dolomite are : (1) important energy resources (2) common rock-forming carbonate minerals (3) oxide minerals of great value (4) minerals used in the manufacture of pencil leads 9. Muscovite Mica minerals are common examples of ……………… silicates. (1) Framework (2) Double chain (3) Sheet (4) Single chain 10. Isotopes are atoms with a variable number of : (1) Electrons (2) Protons (3) Ions (4) Neutrons 11. A qualitative test will reveal : (1) amount of sample. (2) Usefulness of a compound. (3) Identity of a material. (4) Purity of a substance. 12. The measurement of intensity of fluorescence-ray provides a sample and ……… way of ……… analysis. (1) non-destructive , quantitative. (2) destructive , quantitative. (3) destructive , qualitative. (4) non-destructive , qualitative. 13. Piezoelectric effect is when materials produce electric charges when ……… (1) voltage is applied. (2) magnetic field is applied. (3) electric field is applied. (4) mechanical stress is applied. 14. Positron emission involves : (1) a proton and a neutron. (2) a beta-plus particle. (3) a beta-minus particle. (4) an alpha-particle. 15. In positron emission : (1) Z decreases by 1 and A remains the same. (2) Z increases by 1 and A remains the same. (3) Z remains the same and A increases by 1. (4) Z remains the same and A decreases by 1. 16. In alpha decay : (1) Z decreases by 2 and A decreases by 4. (2) Z and A are unchanged. (3) Z decreases by 4 and A decreases by 2. (4) Z decreases by 4 and A decreases by 4. 17. Which statement about the half-life of a radioactive source is correct ? (1) It is the time it take the activity of the source to decrease by half. (2) It is half the time for the radioactive source to become safe. (3) It is half the time it takes the activity of the source to decrease to zero. (4) It is half the time it takes for an atom to decay. 18. Which of the following minerals is noted for its one perfect cleavage ? (1) Pyrite (2) Calcite (3) Muscovite (4) Quartz 19. A geologic feature called a kimberlite indicates the possibility of the presence of which of the following ? (1) diamonds (2) rubies (3) sapphires (4) opals 20. ……………… describes two solid phases (minerals) which can mix in all proportions. (1) Isotopes (2) Polymorphism (3) Solid solution (4) Heavy liquids Put true (√) or false (×) 21. Bromoform's high density makes it useful for separation of minerals by density. (√) 22. Diamonds are the hardest naturally occurring substance on Earth. (√) 23. All minerals are composed of silicon-oxygen tetrahedra arranged in various ways. (√) 24. By definition, petroleum is a mineral. (×) 25. All minerals display a physical property known as fracture. (×) 26. Sulfide minerals are the most rock-forming minerals. (×) 27. Polymorphism refers to two crystalline phases with the same composition but different structures. (√) 28. Pyroxenes and amphiboles are polymorphs. (×) 29. Olivine is a common nesosilicate-single tetrahedron. (√) 30. In the silicon-oxygen tetrahedron there are more oxygen atoms than silicon atoms. (×)  Final 1. Hollow cavities lined with crystals are called ……… (a) massive (b) geode (c) bladed (d) foliated 2. Mineral hardness is a measure of ……… 2021-2022 (a) The mineral's abundance in nature (b) How resistant a mineral is to scratching (c) How well the mineral reflects light (d) How much a mineral weighs 3. A mineral always contains certain elements in definite proportions. This is due to its ……… (a) streak (b) definite chemical composition (c) luster (d) inorganic 4. The minerals, Talc , Muscovite , Quartz and Orthoclase , are similar because they ……… (a) have the same hardness (b) are the same color (c) contain silicon and oxygen (d) break along cleavage planes 5. According to the Bowen's reaction series, which mineral forms at the coolest temperature ? (a) Olivine (b) Pyroxene (c) Feldspar (d) Quartz 6. What do you call a special type of magma that is the source of diamonds ? (a) Granitic magma (b) Basaltic magma (c) Dacitic magma (d) Kimberlite magma 7. Not all minerals crystallize at the same time. What is this called ? (a) Fractional crystallization (b) Surface crystallization (c) Small crystallization (d) Total crystallization 8. Which of the following factors would increase the rate of weathering ? (a) Increasing rainfall (b) Increasing temperature (c) Increasing organic activity (d) All of these 9. Which of these is least likely to form a clay mineral during weathering ? (a) Quartz (b) Olivine (c) Amphibole (d) Feldspar 10. Evaporite minerals are commonly formed in ……… (a) Arid regions where rates of evaporation are high (b) Rain forests where rates of evaporation are low (c) Cold regions that receive significant snowfall (d) An area with frequent volcanic activity 11. The major source of aluminum metal is : (a) Bauxite (b) Hematite (c) Kaolinite (d) Halite 12. ……… is useful for separation of minerals by density. (a) Bromoform (b) Frother (c) Pine oil (d) Modifiers 13. Marble is a metamorphic rock that forms from ……… parent. (a) Granite (b) Limestone (c) Sandstone (d) Shale Which of the following minerals is most stable at the Earth's surface ? (a) Mica (b) Olivine (c) Feldspar (d) Hematite Which of the following minerals has sheet silicate ? (a) Amphibole (b) Olivine (c) Mica (d) Quartz Which silicate structure does pyroxene minerals have ? (a) Independent tetrahedra (b) Single chain (c) Sheet silicate (d) Framework silicate The order that chemical compounds precipitate from sea water is controlled by ……… (a) Density (b) Solubility (c) Molecular weight (d)Valence state Put true (✔) or false (✖) The oxides minerals are the most common groups of minerals in the Earth's crust. (✖) All minerals have cleavage. (✖) The non-metallic minerals have low values of density, ranging between 2.5 and 4.5 g/cc, whereas metallic minerals and ores have densities as high as 20 g/cc. (✖) A mineral can take on a variety of color. (✔) Non-metallic minerals usually opaque and give black or dark-colored streak. (✖) 1. All isotopes of a given element would have the same number of protons but a different number of neutrons. So, their atomic mass is different. 2. The number of oxygen ions involved in the formation of the silicon -oxygen tetrahedron is 4 ions. 3. You would describe the luster of galena, pyrite, silver and gold as metallic. 4. Particles which are identical to the nucleus of a helium atom are called alpha, whereas, electron emissions are called beta-minus. 5. If a mineral breaks along flat or even surfaces , it has cleavage. 6. The mineral property of streak measure or describe color. 7. A classification scheme for minerals based on their chemical composition. 8. Ruby and Sapphire are gems names for the mineral corundum. 9. Name any two minerals formed as a result of evaporation in arid regions ,1- Halite , 2- Gypsum. 10. Interference of light reflected from the surface or from within a mineral is a property called play of color. 11. Fracture is a break in a mineral that is not along a cleavage plane. 12. Ferromagnetic minerals will become magnetized when placed in a magnetic field , and will remain magnetic after the external field is removed.  Summer 1. Which one is a layered silicate mineral ? (a) Hematite (b) Kaolinite (c) Anhydrite (d) Malachite 2021-2022 2. Diamond and Graphite have the same ……… (a) Hardness (b) Composition (c) Properties (d) Structure 3. Dolomite mineral has a composition ……… (a) CaMg(CO3)2 (b) CaCO3 (c) CuCO2 (d) CaSO4 4. Opal is a mineraloid because it is ……… (a) Crystalline (b) Oxide (c) Amorphous (d) Colorless 5. Graphite is a slippery mineral , so it's used as ……… (a) Medicine (b) Lubricant (c) Table salt (d) Toothpaste 6. The most important application of corundum is ……… (a) Glass (b) Agriculture (c) Abrasive (d) Brick-making 7. The characteristic habit of malachite mineral is ……… (a) Foliated (b) Fibrous (c) Dentritic (d) Botryoidal 8. Satin spar is a pearly fibrous variety of ………. (a) Gypsum (b) Calcite (c) Quartz (d) Muscovite 9. Trace impurities of Chromium in beryl are responsible for the deep green of (a) Emerald (b) Ruby (c) Sapphire (d) Amethyst 10. In Opal : Interference of light from submicroscopic layers of spherical SiO2 particles give a property ……… (a) Hardness (b) Iridescence (c) Luminescence (d) Fluorescence 11. Select a mineral that has a dark streak : (a) Galena (b) Calcite (c) Talc (d) Muscovite 12. Select a mineral that has a dull earthy luster. (a) Pyrite (b) Chalcopyrite (c) Kaolinite (d) Quartz 13. Minerals with ……… bonds are the hardest minerals. (a) Van Der Waals (b) covalent (c) metallic (d) ionic 14. Which mineral can be drawn into a wire ? (a) Ductile (b) Elastic (c) Flexible (d) Sectile Put true (✓) or false (✗) 15. A scratch in the softer alteration product reflects true hardness of the mineral. (✗) 16. The same cleavage quality and quantity will be present in all specimens of the same mineral. (✓) 17. Rock forming minerals have more than twice the specific gravity than metallic minerals. (✗) Give a scientific term. 1. Some minerals may replace other existing minerals while preserving the original's habit. (Pseudomorphism) 2. Open cores, lined with different minerals. (Geode habit) 3. Some minerals are always having the same color. (Idiochromatic Minerals) 4. Some minerals, display a multicolored effect when viewed from different angles. (Play of Colors or Iridescence) 5. A way of determining the color of a mineral in powdered form. (Streak) 1. A common mineral has no cleavage but exhibit a conchoidal fracture, is quartz. 2. Calcite has three directions of cleavage planes, whereas, muscovite has one. 3. The purple of amethyst is a variety of quartz mineral. 4. The characteristic feature of labradorite mineral is play of color. , whereas the characteristic feature of magnetite mineral is magnetism. 5. Mineral which reacts with hydrochloric acid, belongs to carbonate minerals group. 6. Piezoelectricity means electricity resulting from pressure. 7. According to magnetic property, minerals are classified as a- Diamagnetic b- Paramagnetic c- Ferromagnetic. 8. Heavy liquids are solutions with high density & low viscosity , they are often used for determination density & for separation mixtures , Examples of these liquids are Thoulets solution , Bromoform solution. 𝟐𝟑𝟖 9. Alfa Decay of 𝟗𝟐𝑼 nucleus give 𝟐𝟑𝟒 𝟗𝟎𝑻𝒉 as daughter nucleus. 10. Factors affect the mineral products of weathering include : a- Resistance of primary minerals to chemical weathering , b- Climate.  Final Diamond has a high melting point because very strong carbon-carbon ……… bonds. 2022-2023 (a) Covalent (b) Ionic (c) Metallic (d) Van der Waals 2. One mineral may have the same chemical composition of another mineral but differ in crystal structure, this feature is called (a) Pseudomorphism (b) Idiochromatic (c) Polymorphism (d) Isotropism 3. Graphite is used as a lubricant due to its (a) Hardness (b) Slippery nature (c) Color (d) Luster 4. ……… is the world's major source of phosphorus (a) Apatite (b) Calcite (c) Halite (d) Dolomite 5. Mafic minerals are enriched in ……… and ……… (a) Silicon and oxygen (b) Aluminum, and potassium (c) Iron and manganese (d) Silicon and hydrogen 6. Sphalerite is the chief ore mineral of (a) Zn (b) Cu (c) Pb (d) Zr 7. The worthless minerals associated with the ore minerals are called ……… minerals (a) Felsic (b) Mafic (c) Gangue (d) Oxide 8. Olivine is a solid solution series mineral whose two most common end members are (a) Hematite-Ilmenite (b) Albite-Anorthite (c) Forsterite-Fayalite (d) Anorthite-Oligoclase 9. The atomic number is not changed by which type of radioactive decay : (a) Beta (b) Gamma (c) Alpha (d) Affected by all forms of radioactive decay 10. Isotopes of an element have a different number of : (a) Protons (b) Neutrons (c) Electrons (d) Atoms 11. The piezoelectric materials used for converting energy are called : (a) Dielectric (b) Transducer (c) Electric (d) Magnetic 12. Materials in which magnetization persists even after the field removed are called (a) Diamagnetic (b) Paramagnetic (c) Soft Ferro magnetic (d) Hard Ferro magnetic In alpha decay : (1) Z and A are unchanged. (2) Z decreases by 2 and A decreases by 4. (3) Z decreases by 2 and A decreases by 2. (4) Z decreases by 4 and A decreases by 4. Put true (✓) or false (✘) Steel, cement and glass are classified as minerals. (✘) The crystal faces of a mineral are the external expression of the mineral's internal atomic structure. (✔) Mafic minerals are usually dark in color and have relatively high specific gravities. (✔) The sulfides are the most important group of ore minerals. (✔) Evaporite deposits are formed via mechanical weathering. (✘) Non-metallic lusters describe minerals that are generally opaque and reflective. (✘) The Mohs' hardness scale is a chart of an absolute hardness. (✔) Less energy is needed to smelt sulfide, oxide, or hydroxide minerals than is required to smelt a silicate mineral. (✔) Give a scientific term. 1. A mineral has replaced another mineral's chemistry with its own without changing the outward shape of the original mineral. (Pseudomorphism) 2. Optical phenomena displayed by the gemstone opal. (Play of color) 3. An optical reflectance effect arises from the fibrous structure of a mineral. (Chatoyancy) 4. The resistance of a mineral to scratching. (Hardness) 5. A mineral may be flattened by hammering without breaking. (Malleability) Complete : 1. Idiochromatic minerals are self-colored due to their chemical composition , whereas allochromatic minerals are other colored due to the presence of impurities. 2. Calcite, will split along three cleavage planes giving a shape called rhombohedral. 3. The best example of mineral has basal cleavage is muscovite. 4. The best example of mineral has cubic cleavage is halite. 5. The non-metallic luster can be subdivided into several categories include : a- waxy b- vitreous c- resinous d- pearly 6. Cleavage is often described by three factors : a- perfect b- good c- fair 𝑾𝒂 7. The most common equation for the specific gravity ( S.G.) of a mineral is 𝑾𝒂 − 𝑾𝒘. 8. There are three different methods of determining a specific gravity include : a- Jolly balance b- Torsion balance c- Pycnometer 9. Chemical analysis of minerals is obtained by a variety of spectroscopic analytical techniques including : a- Inductively coupled plasma mass spectrometer ( ICP). b- Atomic absorption analysis (AAS). c- X-ray Fluorescence (XRF). d- Scanning Electron Microscopy (SEM). 10. Silicate minerals are classified into 7 major groups including : a- nesosilicates , b- sorosilicates , c- cyclosilicates.  Summer Put true (✓) or false (✗) 2022-2023 1. Minerals which have the same chemistry but different crystal structures are called pseudomorphs. (✘) 2. A mineral is identified using only information about where it came from. (✘) 3. Minerals are made of organic materials. (✘) 4. All minerals display a physical property known as cleavage. (✘) 5. All minerals have a crystalline structure. (✔) 6. The presence of some elements, such as iron, always results in a colored mineral. (✘) 7. Muscovite and biotite both form in sheets, but they are different colors. (✔) 8. Economically valuable minerals that provide the raw materials for industry are the most abundant crustal minerals. (✘) 9. Cleavage planes form along the hardest area of mineral's structure. (✘) 10. The simplest test for magnetism is to use a compass. (✔) 11. Streak is the color of the mineral. (✘) ⇢ Streak is the color of the mineral’s powder. 12. During alpha decay, the atomic number (Z) is reduced by two, and the mass number (A), by four. (✔) 13. Mass spectrometry is an analytical tool useful to identify unknown compounds. (✔) 14. Olivine is actually a mineral series, whose two most common end members are albite and anorthite. (✘) 15. Piezoelectricity describes the ability of a mineral to develop electrical charges when put under stress. (✔) Complete : Silicate minerals are classified into 7 major groups including: a- nesosilicates , b- sorosilicates , c- cyclosilicates. When minerals break, they can either split leaving a clean, flat face called a cleavage plane , or leaving a more rough, uneven surface called fracture. Calcite, will split along three cleavage planes giving a 'diamond shape called rhombohedron. When certain minerals are exposed to ultraviolet light, they appear to glow due to a property called fluorescence. You may be able to identify some carbonate minerals like calcite by Acid test. Biomineralization is the process of forming minerals by organisms. Types of gypsum are: a- Selenite , b- Satin spar , c- Alabaster. Positron emission involves the ejection of Beta Plus particle. There are many different types of Spectroscopy used for chemical analysis, include a- Inductively coupled plasma mass spectrometer ( ICP). b- Atomic Absorption Analysis (AAS). c- X-Ray Fluorescence (XRF). Give a scientific term : 1. A measure of a mineral's relative resistance to scratching. (Hardness) 2. The ability of a mineral to be cut into thin pieces with a knife. (Sectility) 3. Bending easily and staying bent after the pressure is removed. (Flexibility) 4. A measure of how much heat it takes to melt a mineral. (Fusibility) 5. Tests in which a small amount of powdered mineral is introduced into the flame and the resulting colors observed. (Flame tests) 6. Tests in which a small amount of powdered mineral is caused to react in the flame with a molten reactive flux of borax or sodium ammonium phosphate. (Bead tests) 7. Spherical rock, with an internal cavity lined with minerals. (Geode Habit) 8. Formation of new minerals directly from the elements within existing minerals under conditions of elevated temperature and pressure. (Regional metamorphism) 9. During which minerals unstable at Earth's surface may be altered to other minerals. (Weathering) Find a characteristic feature for these minerals : 1. Willemite → Luminescence. 3. Magnetite → Magnetism. 2. Labradorite → Play of color (Iridescence) 4. Amethyst → Purple color (Allochromatic mineral)  Final 2023-2024 Put true (✔) or false (✘) : The electromagnetic separation of minerals is an important in ore-dressing process. (✔) Isotropic minerals exhibit the phenomenon of double refraction. (✘) Arsenopyrite mineral if struck or heated, gives off an odor resembling fresh clay. (✘) In the structure of orthosilicate, all the four corner oxygen atoms of SiO44- units are shared with others. (✘) Positron emission involves the ejection of Beta particle. (✔) Minerals which have the same chemistry, but different crystal structures are called pseudomorphs. (✘) The atomic structure of piezoelectric materials is not completely symmetric. (✔) 8. All minerals display a physical property known as cleavage. (✘) All minerals have a crystalline structure. (✔) Cleavage planes form along the hardest area of mineral's structure. (✘) Streak is the color of the mineral in massive forms. (✘) Labradorescence features occur in some specimens of plagioclase. (✔) During alpha decay, the atomic number (Z) is reduced by two, and the mass number (A) by four. (✔) Mass spectrometry is an analytical tool useful to identify unknown compounds. (✔) Because of their lower temperature and high silica content, granitic magmas tend to be highly viscous. (✔) Complete : Calcite mineral and Aragonite mineral are polymorphs. The three varieties of gypsum are a- Selenite , b- Satin spar , c- Alabaster. When minerals break, they can either split leaving a clean, flat face called a cleavage plane , or leaving a more rough, uneven surface called fracture. 4. Meigen test is used to discriminate between Aragonite & Calcite. Alfa decay of 238 𝟐𝟑𝟒 𝟒 82U = 𝟗𝟎𝑻𝒉 as daughter nucleus & an alpha particle 𝟐𝑯𝒆. Certain minerals develop an electric charge when subjected to a temperature change, called pyroelectric minerals, or to stress, called piezoelectric minerals. Depending on the way the tetrahedral units are linked, the silicates are classified into the following types : a- Nesosilicates , b- Sorosilicates , c- Cyclosilicates , d- Inosilicates , e- Phyllosilicates. Endogenic geologic processes include: a- Magmatic , b- Pegmatitic , c- Pneumatolytic , d- Hydrothermal. The chemical composition of sylvite mineral is KCl. Diamond occurs in rare Mg-rich igneous rock called Kimberlite. The common types of heavy liquids are: a- Thoulets solution , b- Bromoform solution. A variety of methods may be used for mineral exploration, including: a- wet chemical analysis , b- spectroscopic techniques. Give a scientific term : 1. A homogeneous mixture of two different kinds of atoms in solid state and having a single structure. (Solid solution) 2. A measure of how easily a small fragment of a mineral melts in the flame. (Fusibility) 3. A natural process resulting in the complete destruction of mineral’s crystal structure leaving the mineral amorphous. (Metamictization OR Mechanical weathering) 4. A measure of mineral’s relative resistance to scratching. (Hardness)  VIP If the density of gold is 19300 kg/m³, what is the specific gravity of gold? VIP