"Avantor"

Feldspar group; good cleavages of pure soda lime feldspar; most show twinning and labradorescence.

Good grade, brass-yellow copper ore, massive.

Brown, fluorescent crystals intergrown in dolomite rock.

Amphibole group; dark greenish black cleavages, somewhat columnar.

Red, earthy, in natural chunk form; common pigment ore.

Bright blue crystalline veins and coatings in a matrix of mixed copper ore.

Pure kaolinite powder, 200 mesh.

Classic “peacock” aluminum ore.

Cut black mica cleavage sheets.

Small 1–1.5 mm crystal, octahedrans or cubes, Mohs” hardness of 10.

Feldspar group; white-to-gray cleavages of sodic plagioclase; some show twinning.

A classroom set that covers the major types of coal.

Clear rhombs showing double refraction.

Classic, white chalk, massive; from Cliffs of Dover, England.

Crystals and crystal sections up to 1", Mohs’ hardness of 9.

Pure, large, transparent-to-translucent cleavages, Mohs’ hardness of 4.