Green tourmaline double crystal — perfectly finished cap. Mineral Collection - Height: 5.2 cm - Width: 4.5 cm- 41 g - (1)

Tourmalines are a group of minerals belonging to the silicate class, in the order of cyclosilicates. The name derives from the Sinhalese turmali, which literally means a mixed bundle, i.e., a stone of various colors, and historically referred to crystals brought to Europe from Ceylon. The crystal belongs to the trigonal system; it is prismatic, very elongated, vertically striped, and sometimes with unequal development at the two ends of the vertical axis. Its color depends on the chemical composition and may not be uniform within the crystal.