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What are minerals? How are minerals identified?. Pyrite or “Fool’s Gold”. Gold. Minerals are …. Nonliving (inorganic), solid substances. They occur natural ly and have a repeating structure (crystal structure due to internal arrangement of atoms). How are minerals used?. - PowerPoint PPT Presentation
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What are minerals?How are minerals identified?
Pyrite or “Fool’s Gold”Gold
Minerals are …
Nonliving (inorganic), solid substances. They occur naturally and have a repeating structure (crystal structure due to internal arrangement of atoms).
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
How are minerals identified?
• Minerals can be identified by their properties. – Color– Streak– Hardness– Luster– Cleavage– Fracture
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
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.
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.
1 2 3 4 5 6 7 8 9 10
Talc Gypsum Calcite Fluorite Apatite Feldspar Quartz Topaz Corundum Diamond
Mohs’ Hardness Scale
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.
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
Fracture
• Fracture is the property of breaking unevenly or along a curved surface.
Copper has an uneven or irregular fracture.
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.
Special CharacteristicsFluorescence
• 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.
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