Minerals Unit 3 Notes. What is a mineral? A mineral must be all of the following: Naturally...
-
Upload
khalil-sapp -
Category
Documents
-
view
219 -
download
0
Transcript of Minerals Unit 3 Notes. What is a mineral? A mineral must be all of the following: Naturally...
What is a mineral?• A mineral must be all of the
following:
• Naturally occurring
• Inorganic solid (not living)
• Definite structure
• Definite composition (what it’s made of)
Crystal StructureHere are the six crystal systems that all minerals belong to:•Cubic – sylvite, halite•Hexagonal – emerald, graphite•Tetragonal – wulfenite, zircon•Orthorhombic – topaz, sulfur•Monoclinic – gypsum, mica•Triclinic – kyanite, turquoise
Name Symbol % By Mass
Oxygen O 46.6%
Silicon Si 27.7%
Aluminum Al 8.1%
Iron Fe 5.0%
Calcium Ca 3.6%
Sodium Na 2.8%
Potassium K 2.6%
Magnesium Mg 2.1%
Others ---- 1.5%
SilicatesThe silica tetrahedron consists of four oxygen atoms packed closely around a single silicon atom. Named for its shape (like a 3D pyramid).
How do minerals form?
• 3 Ways:–Cooling of molten rock (lava or magma)
–Evaporation of liquid
–Saturated solutions
Mineral Crystal Size
• Small Crystals – indicates slow cooling of molten rock
• Large Crystals – indicates fast cooling of molten rock
Mineral Identification
• Color – color is the first property you notice – this is usually the 1st step in identification, but the least useful
Factoid
•What is the hardest substance on Earth??
• A diamond is the hardest substance
(10 on Moh’s scale)
1010 DiamondDiamond
99 CorundumCorundum
88 TopazTopaz
77 QuartzQuartz
66 FeldsparFeldspar
55 ApatiteApatite
44 FluoriteFluorite
33 CalciteCalcite
22 GypsumGypsum
11 TalcTalc
Mohs HardnessMohs Hardness ScaleScale
Mineral Identification
• Streak – the color of the powder left when a mineral is rubbed against a hard rough surface (usually unglazed porcelain)
2 Types of Luster
• Metallic – shiny
• Nonmetallic – glassy, brilliant, greasy, oily, waxy, silky, or pearly
Mineral Identification
• Cleavage – mineral breaks along smooth surface
• Fracture – mineral breaks unevenly (jagged)
Mineral Identification
• Acid Test – some minerals give off CO2 (carbon dioxide) when acid is added.
Mineral Usage
• Ore – mineral resource mined for a profit
• Gem – mineral that is beautiful, rare, and valuable