Ключевые слова: aggregate, amethyst, black, block, blue, brush, classic, closeup, cluster, cold, collection, contrast, crude, crystal, crystalline, crystallization, crystals, dark, druse, gem, geology, glass, glassy, group, isolated, jewel, jewelry, jewels, lilac, mineral, mineralization, mineralogy, monochrome, mountain, natural, pebble, quartz, raw, rock, science, semiprecious, shade, silica, stone, transparent, typical, white,