Ключевые слова: amethyst, beautiful, birthstone, chrystal, crystal, crystalline, danburite, diamond, druze, energy, facet, faceted, gem, gemology, gemstone, geological, geologist, geology, healing, igneous, industry, iron, jewel, jewelery, jewelry, manufacturing, metamorphic, mineral, mineralogy, oxide, pink, precious, pyrite, quartz, rock, rough, science, semiprecious, shiny, silica, silicate, silicon, specimen, spiritual, stone, therapy, tourmaline, translucent,