GEOL 1403-
Mineral & Rock
Lab Exam 1 with
100% correct
answers
Olivine
uneven fracture
Hornblende
2 directional cleavage NOT at 90º
augite
2 directions of cleavage AT 90º
, biotite mica
sheet/basal cleavage
quartz
conchoidal fracture; many color varieties
Potassium Feldspar (K Feldspar)
2 directions of cleavage AT 90º; exsolution lamellae common
Plagioclase feldspar
2 directions of cleavage AT 90º; striations common
calcite
3 directions of cleavage NOT at 90º (rhombic); reacts with HCl acid; double
refraction
Mineral & Rock
Lab Exam 1 with
100% correct
answers
Olivine
uneven fracture
Hornblende
2 directional cleavage NOT at 90º
augite
2 directions of cleavage AT 90º
, biotite mica
sheet/basal cleavage
quartz
conchoidal fracture; many color varieties
Potassium Feldspar (K Feldspar)
2 directions of cleavage AT 90º; exsolution lamellae common
Plagioclase feldspar
2 directions of cleavage AT 90º; striations common
calcite
3 directions of cleavage NOT at 90º (rhombic); reacts with HCl acid; double
refraction