"STEM kits"

Earthy, yellow brown iron ore.

Obsidian is hard black colored, volcanic glass.

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

Porphyritic igneous rock containing biotite, feldspar, and hornblende.

Pumice is light colored glassy rock that floats in water.

Conglomerate is a sedimentary rock made up rounded quartz pebbles.

Gray to white metamorphosed carbonate rock.

Muscovite is a mica mineral cut to demonstrate basal cleavage.

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

Chert is a microcrystalline, hard, silica mineral.