Ключевые слова: abrasive, andalusite, anisotropic, black, blue, colorless, crystal, crystalline, decorative, earth, elongated, garnet, gem, gemstone, geological, geology, industry, insulator, kyanite, macro, material, metamorphic, mineral, natural, nature, ore, out a bar, pegmatite, porcelain, precious, raw, rock, rough, sample, science, sillimanite, specimen, stone, structure,