1. Minerals 1. Natural 2. Solid 3. Inorganic 4
Minerals 1. Natural 2. Solid 3. Inorganic 4. Definite chemical composition 5. Crystal structure due to internal arrangement of atoms

2. Minerals There are about 4000 known minerals
Minerals are made of elements (either a single element or a combination of elements)
Examples of Minerals
Gold: a mineral made of one element (gold…Au)
Calcite: a mineral made of 3 elements (calcium, carbon, and oxygen…CaCO3)

3. Minerals are identified by their key characteristics called PROPERTIES
hardness
crystal shape (form)
luster
color
streak
cleavage/fracture
density (specific gravity)
special properties --reaction to acid --fluorescence salty taste magnetism

4. MINERAL HARDNESS Ability to scratch another mineral
Mohs scale from 1 (talc) to 10 (diamond)
Quartz (most common mineral and most dust particles) is 7

5. Mohs Mineral Hardness Scale
1) Talc 2) Gypsum 3) Calcite 4) Flourite 5) Apatite 6) Feldspar 7) Quartz 8) Topaz 9) Corundum 10) Diamond
Softest
Hardest

6. Minerals Are Crystalline
Geometrical crystal shapes suggest ordered structures.

7. LUSTER Describes how light reflects off the surface
Main categories are “metallic” and “non-metallic”

8. COLOR
results from ability to absorb some wavelengths and reflect others

9. STREAK Color of the powder when rubbed on a “streak plate”
Some paint is based on powdered minerals (streaks).

10. MINERAL CLEAVAGE/FRACTURE
Some minerals split along flat surfaces when struck hard--this is called mineral cleavage
Other minerals break unevenly along rough or curved surfaces--this is called fracture
A few minerals have both cleavage and fracture
MINERAL CLEAVAGE/FRACTURE

11. Special Characteristics-- the “Acid Test”
Carbonates react with dilute HCl and other acids by fizzing or bubbling (releasing CO2 gas)

12. Special Characteristics-- Fluorescence
Some minerals will glow when placed under short-wave or long-wave ultraviolet rays
Franklin and Ogdensburg NJ are famous for their fluorescent minerals