Échantillons

Dark brown to black; polycrystalline zinc ore.

Exemplary display of hexoctahedral crystal shape.

Feldspar group; calcium end member plagioclase crystals in pyroxene matrix.

Brown, fluorescent crystals intergrown in dolomite rock.

Black, high grade, foliated, greasy feel.

Brown, earthy, massive; used for yellow pigment.

Light gray, compact, hard, opaque, microcrystalline silica mineral.

Clear, euhedral points and sections.

Gemmy, sherry-colored crystals and sections approximately 3/8– 1/2"

Spinel group; iron-black, massive; natural magnet.