Minerals – Study Sheet
Vocabulary:
element
compound
mineral
inorganic
silicate
silica tetrahedron
luster
metallic
carbonate
streak
cleavage
fracture
Moh’s Scale
hardness
Things to study:
1. 8 elements make up most of earth’s crust: oxygen, silicon, aluminum, iron, calcium,
sodium, magnesium, potassium (see ref. tables, p. 11)
2. Oxygen is the most abundant element in Earth’s crust.
3. Silicon is the second most abundant element in Earth’s crust (by mass).
4. Five characteristics of a mineral are: solid, naturally occurring, crystalline, inorganic,
definite chemical composition
5. Silicate group is the most common type of mineral in Earth’s crust.
6. Silicon- oxygen tetrahedron is the basic unit of the silicate mineral.
7. 4 oxygen atoms, 1 silicon atom make up the tetrahedron.
8. The shape of a tetrahedron is 4 sides, each side is a triangle (pyramid).
9. Arrangement of the atoms determines all physical properties of a mineral.
10. Minerals with the same composition can be different because they have their atoms
arranged differently.
11. To find a silicate mineral on the reference tables p. 16 - look for any that have BOTH
Si and O in the chemical formula. (there are 10)
12. To identify a carbonate mineral on the reference tables, look for those that have
BOTH C and O in the chemical formula (calcite, dolomite)
13. Carbonate minerals can be identified by using the acid test.
14. Color is not a very good identifier because some minerals are the same color or
sometimes the same mineral appears as different colors.
15. The two main categories of luster are metallic and nonmetallic.
16. Metallic means it looks like metal.
17. Some common nonmetallic lusters are: glassy (very shiny), waxy (some shine), dull
(not shiny)
18. Streak is the color of the powder of a mineral
19. To do the streak test: put streak plate on flat surface, rub mineral over the streak
plate, rub finger over streak plate to pick up powder, look at the color of the powder.
20. A mineral may have no streak if it is too hard.
21. Streak is always the same for a particular mineral, color can change, so streak is
better than color.
22. There are only 6 different crystal shapes so many minerals have the same crystal
shape.
23. Cleavage looks like it has been cut – breaks along one or more flat surfaces. Fracture
means that it breaks irregularly – no flat surfaces.
24. Hardness is the resistance to being scratched
25. Moh’s Scale is used to determine hardness of a mineral.
26. Low numbers on Moh’s scale = soft, high = hard.