Chapter 2 Chapter 2 Minerals Reading: 2.1-2.6
Feb 19, 2016
Chapter 2
Chapter 2 Minerals Reading: 2.1-2.6
Relationships to Earth Systems
• Biosphere• Hydrosphere• Atmosphere• Lithosphere
1) Calcite Limestone,2) Halite,3) Clay minerals
2.1 What is a Mineral?
• A mineral is a naturally occurring, inorganic solid, with a definite chemical composition and crystalline structure.
Is Ice a Mineral?• According to our definition?• Naturally occurring? • Inorganic? Solid?• Chemical composition ?• Crystalline structure?
2.2 Chemical Composition • First lets go to Atoms !• All matter is made of Atoms.• Every speck of Gas, liquid, or
Solid surrounding you is a mix of millions of Atoms.
Atoms and Elements
“The Big 8” Most Abundant Elements in Earth Crust
Charging Particles: Ions Positive Charge +
Cation(1-8)
Negative Charge –Anion(1-4)
Other Bonds
• Covalent BondBetween 2 Nonmetals neither one donates or gives up an electron, They simply Share in outer orbital shell forming Covalent bond
• Metallic Bond very few electrons in the outer most electron shells. Instead of donating or sharing these electrons are released from the orbital shell and available for a nearby cluster of atoms to use. “floting in a sea of Electrons”
Formulating Compounds
• SiO2
• (Mg, Fe)2SiO4
2.3 Crystalline Nature of Minerals• A crystal is any substance whose atoms are
arrange in a regular, periodically repeated pattern.
• When atoms combine to form minerals they so in organized way that forms a geometric pattern called crystal.
Crystals
Minerals and Rocks
• Room 222 ( Geology Building).
• Geology Building lobby
• Museum ?
Physical Properties of Minerals 1 Crystal habit (shape) 2) Cleavage & fracture 3) Hardness 4) Specific gravity 5) Color 6) Streak 7) Luster Others (Taste, Reaction to Acid, magnetism. )
Crystal Habit
Quartz: elongated crystals Quartz: no characteristic shape
Cleavage & Fracture
Mohs Mineral Hardness Scale
Specific GravityQuartz 2.7
Au 19
Color
Luster
Other
Mineral Classes
Silicates
Si
O
OO
O
Carbonates
2.6 Commercially Important Minerals
Important Minerals
2.7 Harmful and Dangerous Roks and Minerals
• Asbestos.
• Feldspar Quartz
Next Class
• Rocks