Minerals Flashcards
Structure of olivine
(Mg, Fe)2 SiO4
Magnetism
Most minerals not magnetic except magnetite
What is specific gravity
Expression of density in relation to density of a standard or reference
Cleavage
Tendency to break along planes of weaknesses inherited from their crystal
Cleavage degree
Perfect, good, bad + number of cleavage directions
Fracture
Nature of the surface formed when a mineral is broken along a direction other than the cleavage
Conchoidal fracture
Curved like broken glass or shells
Hackly fracture
Like broken iron
Gypsum cleavage
1 perfect and 2 distinct cleavages ( none at 90)
Calcite cleavage
3 cleavages at 60
Feldspar cleavage
2 distinct cleavages at 90
Magnetite cleavages
Uneven fracture
Native copper
Hackly fracture
Opal
Conchoidal fracture
Quartz fracture
Conchoidal fracture
Lustre
Light reflection off the surface of a mineral
Lustre types
Metallic
Vitreous (glassy)
Pearly
Greasy
Silky
Adamantine (diamond)
Dull
Tourmaline cross section colour
Orange brown
Orthopyroxene Cross section colour
Pink
Hornblende cross section colour
Green
Biotite cross section colour
Brown
Pyrite lustre
Metallic
Calcite lustre
Vitreous
Diamond lustre
Adamantine
