1. What is a Mineral?

2. What is a mineral? Properties:
Solid
Cannot be a liquid or a gas
Naturally Occurring
Found in nature, not man-made
Inorganic
Is not alive and never was, non-living
Fixed composition
Has a chemical formula, most are formed from compounds of two or more elements, some minerals consist of one element ex. Au
Crystal Form
A definite structure in which atoms are arranged

3. What is a mineral? Definition:
A mineral is a naturally formed, inorganic solid that has a definite crystalline structure.

4. The next few slides show an assortment of items.
Questions to ask yourself when determining if an item is a mineral or not:
Is it non-living material?
Is it a solid?
Is it formed in nature?
Does it have a crystalline structure?
The next few slides show an assortment of items.
As a group, categorize the items as either:
Minerals or Non-Minerals.

5. Wood

6. Gold

7. Fossil

8. Topaz

9. Bones

10. Granite

11. Quartz

12. Pearls

13. Talc

14. Icebergs

15. Diamond

16. Coal

17. Rock Salt

18. And the answers are… Minerals Non-Minerals Gold Topaz Quartz Talc
Iceberg*
Diamonds
Non-Minerals
Wood - once living
Fossils – once living
Bone - living material
Granite - intrusive igneous rock
Pearls – made by oysters
Coal - Sedimentary rock
Rock Salt – Sedimentary rock
According to IMA – ice is listed as a mineral

19. Two Groups of Minerals Nonsilicates Silicates
Do not contain combinations of Si and O
May contain C, O, F, S
Classes of Nonsilicates
Native Elements: Au, Cu, Ag
Oxides : Al or Fe combine with O
Carbonates: C + O
Sulfates: S + O
Halides: F, Cl, I, or Br combine with Na, K, or Ca
Sulfides: Pb, Fe, Ni, combine with S
Silicates
Contains Silicon (Si) and Oxygen (O)
90% of Earth’s crust
Combine with elements such as Al, Fe, Mg, and K

20. Identifying Minerals
Color – the same mineral can come in a variety of colors, not reliable

21. Luster – the way in which a mineral reflects light
Metallic - opaque and reflective, like metal
Submetallic - to nearly opaque and reflect well
Nonmetallic - not looking like a metal at all
Vitreous - glassy
Silky - fibrous
Resinous – yellow, dark orange, brown
Waxy
Pearly – like inside a mollusk
Earthy – dull, looks like dirt or clay

22. Examples of luster:

23. Streak – the color of the mineral in a powdered form
Cleavage – when minerals break along a smooth, flat surface
Fracture – when minerals break unevenly along a curved or irregular surface

24. Hardness – a minerals resistance to being scratched
Moh’s Scale of Hardness

25. Density – how much matter is in a given amount of space
Special Properties
Fluorescence – glow under ultraviolet light
Chemical Reaction – fizzes with acid test
Optical Properties – double image formed
Magnetism – magnetic, attract iron
Taste – salty
Radioactivity – radium or uranium contained

26. Fluorescent Minerals:
Some minerals fluorescence in pure samples, other require “activators” to
fluorescence.

27. “Fizzes” with HCl acid:
The chemical reaction indicates there is presence of a carbonate mineral
(like calcite or dolomite)

28. Double Image:

29. Magnetism: Iron filings and nails attracted to magnetite

30. Follow up Questions to Mineral ID Lab:
1. Which mineral was the easiest to identify? Which trait or traits made this mineral easy to identify?
2. Which two minerals were the most difficult to tell apart?
What traits did these minerals have in common?
What trait or traits did you have to use to determine the names of these minerals?
3. What trait would be easiest for a field geologist to determine? Why?

31. 4. What trait would be hardest for a field geologist to determine? Why?
5. If you were a field geologist, what tools would you want to take on a job that would require you to distinguish between fluorite, calcite, quartz, and gypsum?
Why are each of these tools important?