bicolour tourmaline crystal mineral on black background

bicolour tourmaline crystal mineral black background turmaline turquoise semiprecious topaz geologic colorful stone bicolor conglomerate crystals emerald gemstone multicolor watermelon geologist jewelry expensive africa zaire precious transparent specimen rock gem geology mineralogy pegmatite hydrothermal silicate colour sample ore green glass mine gemmy glassy white red multi aggregate crystalline elbaite cluster shiny alternative healing