Ключевые слова: agate, alternative, amethyst, birthstone, carat, chalcedony, citrine, crystal, earth, facet, faceted, gem, gemmology, gemology, gemstone, geode, geologic, geological, geology, green, hardstone, healing, igneous, jewel, jewellery, jewelry, jewels, lichen, metamorphic, mined, mineral, moss, mossagate, natural, nature, polished, precious, quartz, rock, semiprecious, silica, spiritual, stone, uncut,