What is a mineral
Naturally occurring
Inorganic
Solid
Definite chemical composition ( element or compound )
Regular crystalline structure ( repeating atomic structure )
What is a rock
An aggregate of minerals
What are crystals
Regular patterns caused by cooling liquids
What is glass
Amorphous by rapid cooling
Calcite
CaCO3
Quartz
SiO2
Pyrite
FeS2
Galena
PbS
Native surfer
S
Native copper
Cu
Hardness
Hard minerals scratch softer minerals
Use MOHs hardness scale
Lustre
Appearance of mineral depending on its ability to reflect light
Streak
A mineral specimen is scraped across unglased porcelain (streak plate) and a powder if left behind
Cleavage
Plane of weakness in a minerals atomic structure
Fracture
Minerals that break along an irregular surface fracture and do not have a cleavage
Euhedral
Well defined mineral shape with edges
Anhedral
A mineral with no straight edges irregular
Twinning
2 or more crystals are grown within the same mineral but in different directions
