Physical Properties of Minerals
Crystal form: most minerals have crystal form however may not be perfect because crystals that form at the same time compete for space
Luster; appearance or quality of light reflected from surface of mineral
Metallic
Nonmetallic
Glassy
Earthy
Color; least reliable; light, intermediate, dark
Streak; color of powdered form of mineral
Hardness; resistance of a mineral to abrasion; rub a mineral against object of known hardness
Mohs scale
Talc
Diamond
Cleavage: tendency to break along a smooth, flat surface; represents planes of weak internal chemical bonds
Fracture; tendency of mineral to break irregularly; mineral has no chemical bonds that are stronger than others (quartz); conchoidal fracture
Specific gravity; weight of mineral to weight of equal volume of water
Other properties
Taste
Smell
Elasticity
Feel
Magnetism
Reaction to HCL
Silicates
Most abundant mineral group
Silicon-oxygen tetrahedron
Building block of silicates
Common silicate minerals
High iron silicates; pyroxene, amphibole, biotite