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Published byAlannah Franklin Modified over 9 years ago
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What are minerals? How are minerals identified? Pyrite or “Fool’s Gold” Gold
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Minerals are … Nonliving (inorganic), solid substances. They occur naturally and have a repeating structure (crystal structure due to internal arrangement of atoms).
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How are minerals used? Aluminum can be used for packaging, transport, and building. Beryllium is used in gemstones and fluorescent lights. Copper is used in electric cables, wires, and switches. Feldspar is used in glass and ceramics. Calcite is used in toothpaste and construction. Iron is used in buildings, automobiles, and magnets. Titanium is used in airplanes. www.mii.org/commonminerals.php
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How are minerals identified? Minerals can be identified by their properties. –Color –Streak –Hardness –Luster –Cleavage –Fracture
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Color Minerals come in a rainbow of colors. Minerals can change color when exposed to air and rain for a long time. A mineral can have different colors. Color alone cannot be used to identify a mineral. Malachite
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Streak Streak is the color of the powder left behind when a mineral is rubbed against a streak plate. A streak plate is a rough white tile. Pyrite with its greenish- black streak. Hematite with its reddish streak. Galena with its dark gray- black streak.
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Hardness Hardness is a mineral’s ability to scratch other materials or be scratched by other materials. Mohs’ hardness scale ranks minerals from 1 to 10 according to their hardness. Talc, the softest mineral, is 1. Diamond, the hardest mineral, is 10. A mineral can scratch another mineral if its hardness value is greater than or equal to the other mineral’s hardness. 12345678910 TalcGypsumCalciteFluoriteApatiteFeldsparQuartzTopazCorundumDiamond Mohs’ Hardness Scale
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Luster Luster is the way a mineral’s surface reflects light. –Metallic luster (how light reflects off metals such as gold, silver, and copper) –Nonmetallic luster (described as glassy, silky, waxy, pearly, earthy, or resinous-like plastic) Tourmaline has a glassy luster.
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Cleavage Cleavage is the way that some minerals break into pieces with smooth, flat, regular shapes. Quartz is one of Earth’s most common minerals. This crystal forms as a six-sided prism with pointed ends. The ends look like six-sided pyramids. www.sdnhm.org/fieldguide/minerals/index.html
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Fracture Fracture is the property of breaking unevenly or along a curved surface. Copper has an uneven or irregular fracture.
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Special Characteristics “The Acid Test” You can test minerals by putting them in vinegar. If it instantly reacts (fizzing or bubbling – releasing CO2 gas), it is probably a carbonate mineral like calcite.
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Special Characteristics Fluorescence Some minerals will glow when placed under short-wave or long-wave ultraviolet rays. Franklin and Ogdenberg, NJ are famous for their fluorescent minerals. Calcite (red) and willemite (green) Glowing under shortwave ultraviolet light.
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Special Characteristics Magnetism Many iron minerals will produce an invisible magnetic force field. “Lodestone” was used by Vikings more than a thousand years ago as compasses. Magnetite
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