1. Minerals

2. WHAT THINGS AROUND YOU ARE MADE OF MINERALS???
LOOK AROUND THE ROOM
WHAT THINGS AROUND YOU ARE MADE OF MINERALS???
EVERYTHING!!!

3. MINErals
Everything in this classroom and school, and any other man-made structure was mined out of the Earth.
Mining is the extraction of materials out of the Earth’s crust for human use
So…what are minerals?
Rocks? Trees? Diamonds? Oil? Water?

4. Nutritional Definition
Minerals are the natural chemical elements that are required by living organisms to survive.
As in “Vitamins and Minerals”.

5. Economic Definition
Minerals are a concentration of naturally occurring solid, liquid, or gaseous material in or on the Earth’s crust in such form and amount that extraction is economically feasible.
Basically, natural materials that can be mined and sold for a profit

7. Scientific Definition Minerals are…..
Naturally occurring
Inorganic
Solids
They have definite chemical (formula) compositions
They have ordered atomic structures (bonding patterns)

8. Minerals on Earth
Of the 5,000 known minerals there are only a dozen or so rock forming minerals that compose most of the Earth.
These minerals share the most abundant elements in the crust.

9. 4 Ways that minerals form
Crystallization from magma
2. Precipitation from water
3. High pressure and temperature recrystallization
4. Hydrothermal solutions

10. How are minerals identified and classified?
The 4th and 5th parts of the definition…
Definite chemical compositions (formula)
Ordered atomic structures (bonding patterns)
- result in each mineral having a set of unique physical, observable characteristics

11. Physical Characteristics include...
Color
Streak
Luster
Hardness
Fracture and cleavage
Density
*Note that size is not a physical characteristic*

12. Color
Color of some minerals is a very useful characteristic to use in identifying them.
Sometimes it is not
This sulfur for example is almost always yellow.
Quartz can be almost any color

13. STREAK Streak is the color of the mineral in its powdered form.
The powder is left behind when the mineral is rubbed on a piece of unglazed porcelain, the streak plate

14. Luster
Luster is the way in which a mineral reflects, refracts, or absorbs light….in other words the way that it shines.

15. Luster may be Metallic or non-metallic
This is the metallic luster of the mineral Galena.
Metallic means Silver or Gold. Black and shiny is not necessarily metallic

16. Non-metallic lusters
may be earthy,
pearly, glassy, dull,
waxy, resinous, or
silky.

17. Hardness
Hardness is a mineral’s resistance to being scratched.
NOT ITS RESISTANCE TO BREAKING!!!
Tested with fingernail and glass scratch plate

18. A numerical scale (Moh’s) from 1-10 is used to measure the hardness of minerals.
Talc is the softest mineral at #1
Diamond is hardest at #10

19. Procedure for Hardness Test
1.) Does the mineral scratch glass
Yes  hardness is > 5.5
No – go to step 2
2.) Does my nail scratch the mineral
Yes  hardness is < 2.5
No  hardness is between 2.5 and 5.5

20. Cleavage or Fracture
is the way to describe how a mineral breaks.
If the mineral breaks along smooth, flat, parallel surfaces, it is said to have cleavage. “predictable”
If the mineral breaks along rough, irregular surfaces, it is said to have fracture. “random”

21. TYPES OF CLEAVAGE
CUBIC
OCTAHEDRAL
BASAL
RHOMBIC

22. Why do minerals break the way they do?
Minerals that have cleavage do because they break along parallel planes of weakness
This is due to the internal arrangement and unequal bonding of their atoms.
Minerals that fracture have equal (or close to it) atomic bonding in all directions
You can remember a meat cleaver and a bone fracture to keep these terms straight.

23. BASAL -BREAKS IN SHEETSweb

26. Density Density is the ratio of a mineral’s mass to its volume.
Dense minerals, such as Galena, are said to be “heavy for their size”.

27. Remember!!! The physical properties of a mineral are determined by:
1. It’s chemical make-up
2. the arrangement of its atoms.

28. Common Mineral Groups... Silicates
The 2 most abundant elements in the earth’s crust are oxygen and silicon. Si02
These combine to form an atomic structure called a silicate tetrahedron.
Silicates typically form from magma and/or extreme pressure.
Quartz

29. This is a silicate tetrahedron
This is a silicate tetrahedron. It is the building block for the silicate minerals such as quartz and feldspar. Very common building block.
SILICA
OXYGEN

31. Carbonates
A group of minerals in which carbon and oxygen combine to form a carbonate CO3 molecule.
Typically form from precipitation
The test for these is the bubble test. When exposed to hydrochloric acid they release CO2 and they bubble.
Borax
Calcite

33. Oxides are compounds made of oxygen and metal, can form in virtually any geologic setting

35. Sulfates Contain SO4 molecule
Forms from evaporating water (precipitation)
Gypsum var. Selenite

37. Sulfides combinations of one or more metals with sulfur
Sulfides combinations of one or more metals with sulfur . Typically hydrothermal
PbS
FeS2

39. Halides Halite - NaCl Fluorite – Ca2F
Contain a halogen ion from group 7a in periodic table
Ex. F, Cl, Br, and I
Salt water evaporites
Halite - NaCl
Fluorite – Ca2F

41. Native elements Contain one element only
Ex. Gold, copper, silver, etc.
Hydrothermal