Mineralpedia Details for Tourmaline
Tourmaline
Refers to the Tourmaline Group, and is not one single mineral. Common members of the group include Elbalite, Schorl, and Dravite, while lesser known members include Uvite, Liddicoatite, and Buergerite. Most if not all tourmalines are pyroelectric and piezoelectric and will generate a charge in response to temperature and pressure changes, respectively. Tourmalines are highly variable in color and appear generally as prismatic, elongated crystals that are heavily striated.
- Formula
- Ca,Na,K[(Al,Fe2+,Fe3+,Li,Mg2+,Mn2+)3](Al,Cr3+,Fe3+,V3+)6(Si6O18)(BO3)3(O,OH)3(F,O,OH)
- Crystal System
- Trigonal
- Fracture
- Irregular/Uneven-Conchoidal
- Hardness
- 7
- WebMineral
- View Tourmaline
- Mindat
- View Tourmaline
Tourmaline from Himalaya mine, San Diego Co., California, United States
Bi-colored, colorful pink-green zoned Elbaite Tourmaline from the famous, classic locality ofSan Diego Co., the Himalaya mine. This specimen, with typical trigonal outline is complete around the prism axis and only shows flaws on one side. There is no damage except for the imperfections on the backside and of course the break-off pint at the base. It is gemmy, has internal "feathers" and is nicely terminated. Important American locality. Overall 3.5 x 1.7 x 1.6cm.
Tourmaline from Gamatha, Kunar Province, Afghanistan
Slender bi-colored Tourmaline crystal doubly terminated - hemihedral. Excellent gem quality specimen. Overall 4cm x 6mm x 5mm.
Tourmaline from Paprook, Kunar prov., Afghanistan
Beautiful long, 5.5cm, terminated zoned Tourmaline crystal. No damage.
Tourmaline from Shengus, Gilgit-Skardu road, Northern Areas, Pakistan
Deep green zoned Indicolite Tourmaline with a blue, terminated cap. Overall 4.5 x 2 x 2cm.
Tourmaline from Mong Hsu, Shan State, Burma
A complete hemihedral chrome tourmaline terminated on both end. As you can see both sides, however, have detachment points from matrix. The color is a gorgeous deep gemmy emerald green.
