What Is Tourmaline Gemstone | Tourmaline Stone – GIA
Brazilian source famous for vivid blue to green tourmalines colored by copper. Facts. Mineral: Tourmaline; Chemistry: Elbaite Na(Li,Al )Al 6 Si 6 O 18 (BO 3) 3 (OH) 4; Dravite NaMg 3 Al 6 Si 6 O 18 (BO 3) 3 (OH) 4; Liddicoatite Ca(Li 2 Al)Al 6 Si 6 O 18 (BO 3) 3 (OH) 3 F; Chromedravite NaMg 3 Cr 6 Si 6 O 18 (BO 3) 3 (OH) 4; Color: All colors; Refractive index: to ...