Chapter Three- Geology
How can you ID a mineral?
- color -luster -crystal structure -streak -hardness -specific gravity -chemical composition
Silicate minerals
- most common minerals on earth -the silicon oxygen tetrahedron is the fundamental building block of silicate minerals
What is the relationship between the way in which silicon-oxygen tetrahedral bond in micas and the characteristic cleavage of micas?
-Silicon- oxygen tetrahedral bond in micas is parallel -Mica has one strong plane of cleavage and easily splits into sheets
How are minerals formed?
-solidification of a melt -precipitation from gas or water -diffusion -metabolism of organisms *SMDP
Streak
color of powder it makes
How can you determine the hardness of a mineral?
You can determine the hardness of a mineral by measuring its resistance to scratching as compared to the Mohs Hardness Scale.
Specific gravity
density
How are gemstones faceted?
grinding and polishing the stones with a faceting machine
Luster
the way a surface scatters light
Why is glass not a mineral?
Glass is not a mineral because it's atoms are arranged in a non-orderly pattern (it doesn't have a crystalline structure)
Cleavage
How a mineral breaks along preferred planes
What is a mineral?
A mineral is a naturally occurring solid that is homogenous and inorganic. It's atoms are aligned in a crystalline structure in an orderly pattern.
Can you crush a diamond with calcite?
No, you must use tools with diamond tips
What is the Mohs Hardness scale?
The Mohs Hardness Scale says that minerals with hardness of 5 & above can scratch all minerals with hardness of 5 & less. Diamond= 10; Quartz= 7; Gypsum=2
