Rock-Forming Minerals PDF

Lesson 4.1 Rock-Forming Minerals  Learning Competency At the end of this lesson, the given DepEd learning competency should be met by the students. Identify common rock-forming minerals using their physical and chemical properties (S11/12ES-Ia-9).  Learning Objectives At the end of this lesson...

Lesson 4.1 Rock-Forming Minerals  Learning Competency At the end of this lesson, the given DepEd learning competency should be met by the students. Identify common rock-forming minerals using their physical and chemical properties (S11/12ES-Ia-9).  Learning Objectives At the end of this lesson, the learner should be able to do the following: Identify common rock-forming minerals using their physical and chemical properties. Discuss the techniques that are performed to analyze the properties of minerals. Cite examples of common rock-forming minerals. The relationship between minerals and rocks is like rocky road ice cream. It is composed of different ingredients: chocolate, marshmallows, peanuts, and almonds.  A rock is a combination of a unique set of minerals with properties that differentiate them from others. What are these distinct properties that make each mineral unique?  Learn about It Minerals It is a naturally occurring, inorganic, homogeneous solid, with a definite chemical composition, and an ordered crystalline structure. Example of a mineral Learn about It Physical Properties of Minerals  Learn about It Color It refers to certain wavelengths of light that are reflected by the material, in this case, a mineral and is perceived by the observer. It is the most noticeable physical property of a mineral.  Learn about It Three Classification of Mineral Colors 1. Idiochromatic Minerals Self-colored minerals Diagnostic - means that the color of a mineral is constant and it depends on the elements that make up their chemical structure. Examples are malachite (always green), rhodochrosite (always red) and sulfur (always yellow). Learn about It  Learn about It Three Classification of Mineral Colors 2. Allochromatic Minerals Often weakly-colored or colorless in their pure state. For this type, color is not a reliable diagnostic property since small impurities may dramatically alter their color. This includes colorless, milky, smoky, citrine, amethyst, and rose Learn about It  Learn about It Three Classification of Mineral Colors 3. Pseudochromatic Minerals False-colored minerals Their colors are due to light diffraction. In this instance, color may be variable but is an exclusive property of the mineral. Learn about It  Learn about It Streak It is the color of the powdered form of a mineral. It is observed by rubbing the mineral across a streak plate. For mineral identification, this property is more reliable than the color of the mineral since the streak is always the same.  Learn about It Luster It is the appearance of a mineral’s surface and is dependent on how it reflects light. Common luster types are pearly, silky, dull, resinous, earthy, adamantine, vitreous or glassy, and metallic. Learn about It Learn about It  Learn about It Crystal Habit It is the characteristic shape in which a mineral grows and is a projection of the mineral’s crystal structure. Some common habits are acicular, blocky, tabular, fibrous, bladed, dendritic, and prismatic Learn about It Learn about It  Learn about It Cleavage It is the tendency of some minerals to break along flat surfaces. These surfaces have the weakest atomic bonding which means that when you use a hammer to break a mineral, it will always break along these points. Learn about It Learn about It Learn about It  Learn about It Fracture It is the pattern in which the mineral breaks aside from its planes of cleavage. Unlike cleavage, fracture does not break along planes; it just breaks unevenly. Learn about It Learn about It  Learn about It Hardness It is the resistance of the minerals to scratching. For more accurate measurement, Mohs scale of hardness is used which is composed of ten minerals, numbered from 1 to 10 (1 as the softest and 10 as the hardest). Learn about It  Learn about It Specific Gravity It is the is the ratio of a minerals’ weight to the weight of an equal volume of water. The size of the mineral is independent of its specific gravity. Learn about It  Learn about It Chemical Properties of Minerals Solubility refers the ability of a substance to dissolve in a solvent at a specified temperature. Melting point refers to the temperature at which solid turns into liquid.  Learn about It Mineral Groups Based on Chemical Composition Chemical Example Description structure Minerals Elements Most of the minerals here are composed of only one copper, gold, element. Having knowledge about elements enables silver, sulfur scientists to identify bonding possibilities and compounds that can be created. Sulfides Minerals under these group are composed of a metal cinnabar (HgS), joined by a sulfur. Metallic luster is the characteristic pyrite (FeS2) that distinguish them. Halides These are nonmetal groups which consists of fluorite (CaF2), chlorine, fluorine, bromine, and iodine as their main halite (NaCl), chemical constituent. diabolite  Learn about It Mineral Groups Based on Chemical Composition Chemical Example Description structure Minerals Oxides and These are mineral groups composed of one or more cuprite (Cu2O), hydroxides metals joined with oxygen, water, or hydroxyl (OH –) hematite (Fe2O3) Nitrates, It is formed when a metal is combined with carbon, malachite, carbonates, nitrogen and boron. nitratine, borax borates Sulfates One or more metal is combined with a sulfate anhydrite compound (SO4) (CaSO4)  Learn about It Mineral Groups Based on Chemical Composition Chemical Example Description structure Minerals Chromates, Chromate, molybdate, or tungstate substituted the wulfenite molybdate, place of the sulfate group. These minerals are usually (PbMoO4), tungstates brightly colored, brittle and dense. scheelite (CaWO4) Phosphates, One or more metal is chemically combined with the apatite, lazulite, arsenates, phosphates, arsenates, vanadates group. vanadinite vanadates Silicates This is the largest mineral group. Minerals under this dioptase, group have different amounts of silicon and oxygen labradorite  Learn about It Analysis of the Composition and Crystal Structure of Minerals Wet chemical analysis involves dissolving a mineral in an acid and analyzing the solution. Acids are used in wet chemical analysis.  Learn about It Analysis of the Composition and Crystal Structure of Minerals Spectroscopic techniques involve quantitative analysis of mineral components depending on the light absorbance of the compounds. Spectrophotometer  Learn about It Rock Forming Minerals Quartz has a chemical composition of SiO2. It is a glass-like hard substance with white streaks. Feldspar has a chemical composition of XAlSi3O8, where X is potassium (K), calcium (Ca), or sodium (Na). Mica is soft, with hardness ranging from 2 to 2.5. It is easily identified by its perfect cleavage, reducing it to thin smooth flakes.  Learn about It Rock Forming Minerals Pyroxene minerals have a general composition of XY(Al,Si)2O6 where X is calcium (Ca) or magnesium (Mg) and Y is either magnesium (Mg), iron (Fe), or aluminum (Al). Amphibole has a general formula of W0-1X2Y5Z8O22(OH)2 (where W is Na or K; X is Na, Zn, Li, Ca, Mn, Fe 2+, or Mg; Y is Mg, Fe2+, Mn, Al, Fe3+, Ti, Zn, or Cr; and Z is Si, Al, or Ti) and has a dark color with a Mohs hardness ranging from 5 to 6. It is opaque and has a glassy luster.  Learn about It Rock Forming Minerals Olivine is a silicate mineral with a general chemical composition of (Mg,Fe)2SiO4, but calcium, manganese, and nickel can be substituted for magnesium and iron. It occurs as small, light green, glassy crystals. It is commonly used in the gemstone industry as peridot.  Key Points A mineral is a naturally occurring, inorganic, solid material that has definite chemical composition. The physical properties of minerals are color, streak, luster, crystal habit, cleavage, fracture, hardness, and specific gravity. These properties are used for mineral identification. Solubility and melting point are chemical properties commonly used to describe a mineral. The most common rock-forming minerals are quartz, feldspar, mica, pyroxene, amphibole, and olivine.  Check Your Understanding Write true if the statement is correct. Otherwise, write false. 1. A mineral is a naturally-occurring substance. 2. Talc can scratch diamond. 3. A huge mineral has high specific gravity. 4. Bubbles that were formed after pouring an acid to a mineral indicates that the sample is a carbonate mineral. 5. Quartz is a good example of an idiochromatic mineral.  Bibliography Amethyst Galleries Inc. “Mineral Gallery” Accessed April 5, 2018. http://www.galleries.com/default.htm Coenraads, Robert R. 2005. Rocks & Fossils: A Visual Guide. Australia: Weldon Owen Inc. Tarbuck, Edward J. and Frederick J. Lutgens. 2012. Earth Science. 13th Edition. New Jersey: Pearson Prentice Hall. Thompson, Graham R. and Jonathan Turk. 1997. Introduction to Physical Geology. United States: Brooks Cole Publishing. Williams, Linda. 2004. Earth Science Demystified. United States: The McGraw -Hill Companies, Inc.