Minerals

What is a Mineral?

A mineral is a naturally occuring solid formed through geologic processes. Minerals have a definite chemical composition, a highly ordered atomic structure, and each has specific physical properties.


How to Identify a Mineral?


Minerals can be identified based on their properties.

Mineral Properties:
Hardness- The physical hardness of the minerals. It is measured on Moh's scale of hardness 1-10. Talc is a one on Moh's scale as the softest and diamond is a ten as the hardest mineral.
Talc
Talc
Diamond
Diamond

Luster- Metallic or non-metallic surface
Metallic-Very shiny and highly reflective surface. Ex. galena, gold, silver
Sub-Metallic- Shiny but not as much as metallic.
Non-Metallic Surfaces
Vitreous- Glassy surface Ex. quartz
Earthy-Very dull surface Ex. orthoclase, kaolinite

Color- The physical color of the surface
Streak-The color of a mineral when it is in powder form.
Cleavage/Fracture- Breakage of a mineral along planes of weakness in crystal structue. If the mineral breaks with planes it has cleavage and if it breaks with no planes it has fracture.
Specific Gravity- comparison of it's denisty to that of water. Found by displacing water.






growing crystals
crystal systems
hardness
luster
streak
color
cleavage/fracture

mineral families

http://www.rocksforkids.com/RFK/identification.html#Luster
http://en.wikipedia.org/wiki/Minerals
what minerals are used for

mineral example