Ключевые слова: amethyst, birthstone, closeup, crystal, feldspar, gem, gemology, gemstone, geode, geologic, geology, hard, hardness, heal, heartstone, isolated, jewel, jewelry, macro, milky, mineral, nature, oregon, oscillator, piezo, piezoelectric, piezoelectricty, pink, precious, quartz, raw, rhombohedral, rock, rose, semiprecious, shape, shiny, silica, silicon, sio2, sio4, sixsided, spiritual, stone, tetrahedra, transparent, valuable, volcanic, white,