2. What is a Mineral?
The building block of rocks
Naturally occurring (versus synthetic)
Inorganic (no C-H bonds)
Solid (ice is a mineral then, but water is not)
3. What is a Mineral?
Chemical composition & crystalline structure
are the two most important properties of a
mineral
Elements
fundamental component of matter
Cannot be broken down by ordinary means
88 naturally occurring elements in Earth’s
crust
4. Elements of the Earth
8 elements make up
98% of Earth’s crust
Oxygen
Silicon
Aluminum
Iron
Calcium
Magnesium
Potassium
Sodium
5. Elements of the Earth
Some few elements ARE minerals (eg: gold)
Most are comprised of 2 to 5 elements
Held together by + / - electrical charges
Many can vary a little is components
88 elements form over 3,500 minerals
9 rock-forming mineral groups
6. Crystals: the crystalline
nature of minerals
Crystal – any substance whose atoms are
arranged in a periodic, repeating pattern
This pattern is crystalline structure
Unit cell – the smallest group of atoms making up
the unique pattern
Crystal face – flat surface occurring when a
crystal grows freely
Reflects light
Bonding creates crystal structure
9. Physical properties of minerals
Crystal habit
the way crystals aggregate
Cleavage
Some minerals tend to break along flat surfaces
Fracture
The way a mineral breaks other than cleavage
10. Physical properties of minerals
Hardness – Moh’s scale
1 to 10, based on
minerals
Specific gravity
Density relative to water
Color
Obvious, but limited use
Streak
Color of fine powder
Luster
The manner it reflects
light
“Other” properties
11. Mineral classes and
rock-forming minerals
Silicates
Carbonates
Sulfides
Sulfates
Native elements
Halides
Oxides
Hydroxides
Phosphates
12. Mineral classes and
rock-forming minerals
Silicates
Most abundant rock-
forming minerals
Carbonates
Form many sedimentary
rocks
Phosphates
Turquoise
Hydroxides
Bauxite
Halides
Table Salt
Sulfates
Gypsum
Sulfides
Pyrite
Oxides
Hematite
Native Elements
Gold, Silver
14. Igneous
Intrusive (inside)
Cool slowly
Forms from molten
magma
Has visible (large)
crystals
Ex: granite/quartz
Extrusive (outside)
Cool quickly
Forms from lava
Has invisible (small)
crystals
Ex:
basalt/pumice/Rhyolite
Formed from cooling magma
15. Metamorphic
(large – change)
Formed by heat and pressure (physical) OR
By chemical changes which occur through
reaction between rock and outside chemical
Two types of metamorphism:
Contact and regional
Contact happens under the surface when magma
intrudes into the rock
Regional happens on the surface from intense heat and
pressure usually during mountain building
17. Metamorphic
Two types form different characteristics
Foliated have visible bands
Ex: gneiss and slate
Non-Foliated have no visible bands
marble
18. Sedimentary
Formed from Sediment
created by weathering and
erosion of existing rocks
which is then compacted
and cemented
Weathering and erosion
Particles, altered, or dissolved
materials
Transported and deposited
Compaction
Lithification (“glueing”
together)
Four Types
Clastic
Chemical
Organic
Bioclastic
20. Chemical
Formed by Chemical
Processes
Evaporation
Solid forms when
water is evaporated
Halite (salt)/Gypsum
Precipitate
Forms when two
liquids are mixed
limestone
21. Bioclastic
Are formed from
living organisms
shell fragments
Hard-shelled
organisms
Clams, corals, oysters,
etc.
Carbonate skeletons
22. Organic
Formed from living
organisms -
plants/animals
Coal made from
plants
Limestone made
from shells