Tourmaline is a group , which refers to a number of related species and varieties.
The Mohs’ hardness is 7 – 7,5.
Even though Tourmaline has been known since antiquity in the Mediterranean region, the Dutch imported it only in 1703 from Sri Lanka to Western and Central Europe.They gave the new gems a Sinhalese name, Turmali, which is thought to mean “stone with mixed colors”.According to the big variety of colors in which Turmaline appears. Unicolored tourmalin crystals are quite rare.Most show various tones in the same crystal or even different colors.There are colorless tourmalines with black crystal ends,green ones with red crystal ends, and some with different colored layers.
Chrome Tourmaline is a rare, gemstone quality variety of chromium-bearing green dravite. Dravite is one of several specific varieties of the tourmaline group.It is found only in Tanzania.
The most important tourmaline supplier is Brazil (Minas Gerais,Paraiba).Other deposits are in Madagascar, Sri Lanka and Tanzania.
Tourmalin is the birthstone of march.