"College - Geology"

Breccia is a sedimentary rock made up of angular rock fragments.

Gray to white metamorphosed carbonate rock.

Obsidian is hard black colored, volcanic glass.

Massive sedimentary gypsum with a moh's hardness 2..

Calcite is a translucent calcium carbonate mineral, mohs hardness 3.

Gray to tan clastic rock made of silt sized particles.

A favorite of collectors for over 50 years.

Gray metamorphosed shale showing "slaty cleavage".

Fluorite is Green Halide mineral with moh's hardness 4.

Selenite is a Clear gypsum mineral with a moh's hardness of 2.

Pink Gneiss is foliated pink and black bands of biotite.

Pegmatite is igneous rock similar to granite but with larger crystals.

Conglomerate is a sedimentary rock made up rounded quartz pebbles.

Carbonate rock formed by the precipitation from water.

Metamorphosed rock showing foliation and rich in hornblende.

A textbook example of pure crystalline carbon which is extermely soft.