Lesson 2: Physical And Chemical Properties Of Minerals PDF

Lesson 2: PHYSICAL AND CHEMICAL PROPERTIES OF MINERALS Objectives: 1.identify the characteristics of minerals; 2. explain the different physical properties of minerals; 3. characterize the different chemical properties of minerals: 4. discuss the Dana Classification System of minerals; and 5. g...

Lesson 2: PHYSICAL AND CHEMICAL PROPERTIES OF MINERALS Objectives: 1.identify the characteristics of minerals; 2. explain the different physical properties of minerals; 3. characterize the different chemical properties of minerals: 4. discuss the Dana Classification System of minerals; and 5. give examples of the different minerals. Review…. In today’s discussion we will be understanding the basic composition of one of the part of the subsystem, the…… Name the following pictures below. And tell the usage of these object in our daily activities.  We are using these products made from minerals daily. Graphite is the mineral used in wooden pencil. Halite is the mineral found in salt. Your cellphone is made up of different minerals. The cars that we drive, the roads that we travel, the building that we live in, are some examples of products derived from minerals. WHAT ARE MINERALS????  MINERALS Minerals are the building blocks of rocks. Minerals make up the rocks beneath your feet, the soil that supports plants, and the deep rock of Earth’s mantle. Mineralogists use the criteria to determine whether a material is classified as a mineral or not. What are the characteristics of Minerals? Try to arrange the jumbled letters to find the appropriate criteria to determine whether a material is classified as a mineral or not. NLTLAURY NGOIRUCC It is a product of Earth’s natural processes.  It is a product of Earth’s natural processes.  CAIIROGN It must be product of Earth’s physical processes.  It must be product of Earth’s physical processes. SOUENEGOMOH DILOS have definite shape and volume.  have definite shape and volume. ENILLATSYRCE SRTRUCUT __________________________- atoms are arranged in order of increasing pattern.  atoms are arranged in order of increasing pattern. LMCEHAIC NOITOCMOPSI _________________________- represented by chemical formula  _________________________- represented by chemical formula  Characteristics of Minerals 1) naturally occurring- a product of Earth’s natural processes 2) inorganic- it must be product of Earth’s physical processes. 3)homogeneous solid- minerals should have definite volume and rigid shape 4) definite chemical composition— represented by a chemical formula 5)orderly crystalline structure- atoms of minerals are arranged in an orderly and repeating pattern  MINERALS by: Razel M. Ferrer Most minerals are derived and extracted from nature They are crystalline solids with definite shape and structure Minerals are found at home and present everywhere Like in jewelries, toothpaste, make-up and mirror. Minerals are made of chemical elements and compounds Chemical compositions had also been found They are naturally occurring, this we must understand Inorganic in nature, let us add!  There are eight classes of minerals Silicates, oxides, sulfides and halides Sulfates, carbonates, phosphates and mineraloids All minerals on earth fit on these kinds. Minerals are distinguished through their properties But geologists prefer their physical instead Habit, luster, cleavage and hardness Color and streak let’s add on these.  DIFFERENT PROPERTIES OF MINERALS PHYSICAL AND CHEMICAL PROPERTIES OF MINERALS Watch the video about the properties of minerals and get ready for recitation….. Physical Properties  Color mineral’s color may change depending on the surface Color maybe a unique identifying property of certain minerals. There are lots of minerals that share similar or the same color/s. In addition, some minerals can exhibit a range of colors.  Streak color of mineral in powdered form. Note that the color of a mineral could be different from the streak. Streak is a better diagnostic property as compared to color. Streak is inherent to almost every mineral. Color maybe unreliable for identification as impurities within the minerals may give the minerals a different color.  Luster how light is reflected off a surface. it is the quality and intensity of reflected light exhibited by the mineral a. Metallic – generally opaque and exhibit a resplendent shine similar to a polished metal b. Non-metallic – vitreous (glassy), adamantine (brilliant/diamond-like), resinous, silky, pearly, dull (earthy), greasy, etc.  Hardness minerals resistance to scratching it is a measure of the resistance of a mineral (not specifically surface) to abrasion.  What is Mohs Hardness Scale Friedrich Mohs, a German mineralogist, developed the scale in 1812. He selected ten minerals of distinctly different hardness that ranged from a very soft mineral (talc) to a very hard mineral (diamond). Moh’s Scale of Hardness  BREAKAGE CLEAVAGE FRACTURE It is the property of some minerals Some minerals may not have to break along parallel repetitive cleavages but exhibit broken surfaces planes of weakness to form that are irregular and non-planar. smooth, flat surfaces. These planes of weakness are inherent in the bonding of atoms that makes up the mineral.  Crystalline Habit Also known as “structure” Refers to the overall shape or growth pattern of the mineral. It can be described as equant, elongate and platy. Equant –three dimensions of mineral have about the same length, like that a cube or sphere. (i.e garnet) Elongate- forms prismatic-like crystals that are thicker than the needle as in a pencil. (i.e Indicolite) Platy- looks like a flattened and thin crystal (like plate). (i.e Wulfenite)  Garnet Indicolite Platy ( Equant) ( Elongate) ( Wulfenite) Additional Properties  Magnetism - Some minerals are attracted to a hand magnet. To test a mineral for magnetism, just put the magnet and mineral together and see if they are attracted. Magnetite is the only common mineral that is always strongly magnetic.  Reaction with Acid Some minerals, especially carbonate minerals, react visibly with acid. (Usually, a dilute hydrochloric acid [HCl] is used.) When a drop of dilute hydrochloric acid is placed on calcite, it readily bubbles or effervesces, releasing carbon dioxide  Striation presence of very thin, parallel grooves. The grooves are present in only one of the two sets of cleavages and are best seen with a hand lens. They may not be visible on all parts of a cleavage surface. Before you decide there are no striations, look at all parts of all visible cleavage surfaces, moving the sample around as you look so that light is reflected from these surfaces at different angles.  Specific Gravity is the weight of that mineral divided by the weight of an equal volume of water. The specific gravity of water equals 1.0, by definition. Most silicate, or rock-forming, minerals have specific gravities of 2.6 to 3.4; the ore minerals are usually heavier, with specific gravities of 5 to 8. For most minerals, specific gravity is not a particularly noteworthy feature, but for some, high specific gravity is distinctive (examples are barite and galena).  Taste, Odor, Feel - Some minerals have a distinctive taste (halite is salt, and tastes like it). Some a distinctive odor (the powder of some sulfide minerals, such as sphalerite, a zinc sulfide, smells like rotten eggs), and some have a distinctive feel (talc feels slippery). Chemical Properties of Minerals  The Dana System Dana's System systematically arranged the 352 mineral species known at the time first by their chemistry (elements, halides, sulfides, silicates, etc.), and then by their atomic structure or symmetry of the atomic arrangement. Dana published his list in 1837 in A System of Mineralogy.  James Dwight Dana American geologist, mineralogist, and naturalist who, in explorations of the South Pacific, the U.S. Northwest, Europe, and elsewhere, made important studies of mountain building, volcanic activity, sea life, and the origin and structure of continents and ocean basins. The main thrust of Dana’s effort was geological. Among his many publications were the text Manual of Mineralogy (1848) and three editions of A System of Mineralogy (1st ed., 1837), including a complete revision in which he founded a classification of minerals based on mathematics, physics, and chemistry. CLASSIFICATION OF MINERALS  The Dana system divides minerals into eight basic classes. The classes are: native elements, silicates, oxides, sulfides, sulfates, halides, carbonates, phosphates, and mineraloids. This classification shows the chemical composition of minerals.  NATIVE ELEMENTS These minerals are naturally occurring in nature in an uncombined form with a distinct mineral structure. It can be classified as metal, semimetals and non- metals.  SILICATES This is the largest group of minerals. It contains silicon and oxygen, with some aluminum, magnesium, iron and calcium.  OXIDES It is form from the combination of a metal with oxygen. This group ranges from dull ores like bauxite to gems like rubies and sapphires.  SULFIDES These are made of compounds of sulfur usually with a metal. They tend to be heavy and brittle.  SULFATES These are made of compounds of sulfur combined with metals and oxygen. It is a large group of minerals that tend to be soft, and translucent.  HALIDES They form from halogen elements like chlorine, bromine, fluorine, and iodine combined with metallic elements. They are very soft and easily dissolved in water.  CARBONATES These are a group of minerals made of carbon, oxygen, and a metallic element.  PHOSPHATES Combination of phosphorus and oxygen. They are often formed when other minerals are broken down by weathering. They are often brightly colored.  MINERALOID It is the term used for those substances that do not fit neatly into one of these eight classes.