| Pyrite |
shaped as flake and strawberry |
highest, easy to identify |
| quartz |
exists as a primary matrix and distribute in a large area |
lower brightness |
| feldspar |
albite is shaped regularly; |
|
| potassium feldspar always occurs between quartz grains |
similar to quartz. specifically, albite has a lower brightness
than quartz; potassium feldspar possesses a brighter gray scale than
that of quartz. |
|
| calcite |
generally formed in a regular rhombic shape |
darker
than quartz |
| dolomite |
shaped
as a regular diamond |
slightly lower than calcite |
| chlorite |
exists in laminated or disorderly
stacked state |
lighter than quartz, but second to pyrite
due to the iron contained
in chemical formula |
| illite |
tends to bend; generally shaped as strip and plate, sometimes
irregular |
slightly higher than quartz, feldspar, and
carbonate minerals. |
| OM |
irregular |
Darkest as black-gray |
