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

Clear, pure cleavages, Mohs’ hardness of 2.

Feldspar group; pink cleavages showing perthitic texture, common potassium feldspar, Mohs’ hardness of 6.

Pure kaolinite powder, 200 mesh.

Cleaned, pure, bright, metallic native copper.

Amphibole group; black, coarse, massive.

Brown, fluorescent crystals intergrown in dolomite rock.

Deep blue, massive, with nepheline; key feldspathoid.

Clear, euhedral points and sections.

Great for geology hardness tests.