6mm Tourmaline quartz bullet bracelet from Brazil.

Tourmaline (quartz) is a group of minerals, all cyclosilicates. The minerals in this group share a characteristic chemical formula: AX3Y6(BO3)3 Si6O18(O, OH, F)4. The A may contain calcium or sodium. The X can be aluminum, iron, lithium or magnesium. The Y is normally aluminum, but can also be chrome or iron. There may be some potassium in the position of A, manganese may be in X, and vanadium may be found in Y, but these elements are uncommon in tourmaline group formulas. Tourmaline occurs in pegmatites, metamorphites, magmatites and alluvial deposits. Although tourmaline was already known in the Mediterranean in ancient times, it was only imported from Sri Lanka in 1703 by the Dutch in Western Europe. They named the new gemstone with a Sinhalese word "Turmali", which means "stone of mixed colors". Rubellites were traditionally used as gemstones - they were used by artists as a talisman, because they would increase the creativity of artists. Tourmalines have certain unique properties.