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.
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.
Bright metallic cubic cleavages; lead ore.
