LESSON 3_ ROCK FORMING MATERIALS Flashcards
is inorganic substance that are made up of one or a number of chemical elements with a definite chemical composition. It is also not man made
Minerals
Physical Properties of Minerals
- Color
- Hardness
- Luster
- Streak
- Specific Gravity
- Fracture
- Cleavage
- Crystal form
Refers to how light is reflected from the surface of a mineral.
Luster
Luster: Shiny, Sparkling
Metallic
Luster: Dull, Greasy, Vitreous, Glassy
Non- Metallic
The ability of mineral to resist scratching.
Hardness
A German mineralogist who developed a hardness scale over 100 years ago.
Friedrich Mohs
Measures the scratch resistance of various minerals from a scale of 1 to 10, based on the ability of a harder material/mineral to scratch a softer one.
Mohs Scale
Mohs Relative Hardness Scale: It flakes easily when scratched by a nail
1
Example of Mohs Relative Hardness Scale 1
Talc/ Talcum powder
Softest known material
Mohs Relative Hardness Scale: A fingernail can easily scratch it
2
Example of Mohs Relative Hardness Scale 2
Gypsum
Ingredient of Plaster
Mohs Relative Hardness Scale: A fingernail cannot scratch it, but a Copper penny can
3
Example of Mohs Relative Hardness Scale 3
Calcite
FOund in Cement
Mohs Relative Hardness: A steel nail can easily stratch it
4
Example of Mohs Relative Hardness Scale 4
Fluorite
Found in toothpastes