Rock & Mineral Test without Identification cuz we did that already

<=important <<=probably on test/hard to remember

Geosphere<

1. **Crust**

\-continental=granite

least dense, most Sio2 (silicate)

\-oceanic=basalt

more dense, less Sio2


2. **Mantle**

\-Peridotite

Denser, less Sio2


3. **Core (inner & outer)**

\-inner solid, outer liquid

\-iron nickel alloy

denser, less Sio2

Layers formed from:

**Differentation**

Early when Earth was molten, heavy elements fell to core, & light rose to surface

Heavier vs. Lighter Materials<

Heavier Mats (inner & outer core)

Iron Fe

Nickel Ni

Lighter Mats (crust)

Oxygen O

Silicon Si

How do geologists know the Earth’s material composition?

Haven’t dug past crust yet

Earthquake=seismic waves

\-speed & direction determined by mats of earth

\-Geologists record waves to determine mats of Earth

2 most common elements

Silicon & Oxygen

Common Minerals of Earths Crust<

__Oxygen 46.6%__

__Silicon 27.7%__

__8 elements make up 98.5% of crust__

Aluminum 8.1%

Iron 5%

Element vs. Compound

Element: Substance that can’t be broken down any simpler by chemical means

\-made of atoms (building blocks of all matter that can’t be split further)

Compound: Substance made of 1-2 Elements

\-most minerals made of compounds

5 Part Definition of Mineral<

1. **Naturally occurring** (natural geologic processes)
2. **Generally Inorganic**
3. **Solid Substance** (ice, mercury are exceptions)
4. **Orderly crystalline structure** (atoms (ions) arranged in orderly, repetitive matter, like crystals, unlike obsidian & glass)
5. **Definite chemical composition that allows some variation** (some vary within defined limits, can substitute for similar size without changing comp.)

5 Mineral Groups<<

1. Silicates-Si+O
2. Carbonates CO3
3. Native Elements-Single element
4. Oxides-O+metals
5. Sulfides-metal+S
6. Sulfates-SO4

Physical Properties<

\-__Color:__ Visible color, how min. samp. appears to naked eye

\-__Streak:__ Color in powdered form, tested by rubbing against unglazed ceramic plate for mineral streak

\-__Luster:__ Way in which light reflects off mineral surface

\-__Breakage:__ Way in which a mineral sample tends to break

*Cleavage:* Tendency of min. to break along flat planes of weakness

*Fracture:* When mins. break unevenly along rough or curved surfaces

__-Hardness:__ Minerals resistance to being scratched, determined by Moh’s scale of hardness 1-10 using common objects

Ex: Penny 3, glass 5.5

__-Crystal Shape:__ External expression of minerals internal atomic structure

Flat, planer surfaces=crystal faces Ex: quartz 6 sides, Pyrite Cubic

__-Specific Gravity:__ Way mineralogists talk about mineral density (in water)

__-Special properties__

__Smell:__ Sulfur

__Double refrac & reacts HCL__: Calcite

__Magnetism__: Magnetite

__Fluorescence UV:__ Flourite

__Taste__: Halite (salty)

__Feel__: Talc (Soap)

Physical Properties determined by:<

Chemical comp & internal structure

3 ways minerals form<<

1. **Precipitation Process**=from solutions of water with dissolved atoms/ions in it
2. **Magma process**=from magma cooling

\-magma cools→atoms in liquid magma slow & bond into solid mins.


3. **Pressure Process**=from heat & pressure without melting

\-Existing mins. bonds break & change deep in Earth at tectonic plates to form new mins

Rocks<<

Rock: Naturally occurring solid made of minerals or mineral like mats.

Most are aggregates of different mins.

Agragate: Whole formed by combining several (typically different) elements

Not Aggragates:

\-different crystals same 1 min.

\-non min. materials, shells, small pieces older rocks, disorganized mass of elements

Mostly Minerals→Rock

Rock Cycle Practice, Thanks Theo

__https://docs.google.com/presentation/d/15oWSPU0PS9qw-5bdP4twhQs7HcbuLM4raXozF1NwPDM/edit?usp=sharing__