Rough Tourmaline

About

Rough Tourmaline is an extremely popular gemstone; the name Tourmaline is derived from Turamali, which is thought to mean "stone with mixed colors." Color is king for tourmaline, which is found in more shades and hues than any other gem. It varies in transparency and color to a substantial extent. split Rough Tourmaline: Rough Tourmaline is an extremely popular gemstone; the name Tourmaline is derived from Turamali, which is thought to mean "stone with mixed colors." Color is king for tourmaline, which is found in more shades and hues than any other gem. It varies in transparency and color to a substantial extent. Crystals of tourmaline may be of different colors in different portions or uniform color throughout, which makes them appealing. General Information: Tourmaline Varieties: Buergerite, Chrom Dravite, Dravite, Elbaite, Feruvite, Foitite, Liddicoatite, Magnesio Foitite, Olenite, Povondraite, Rossmanite, Schorl, Uvite, Vanadium Dravite. Chemical Formula Na (Li 1.5 Al 1.5 ) Al 6 (Si 6 O 18 ) (BO 3 ) 3 (OH) 3 (OH) Lustre Vitreous Mohs Hardness 7 to 7.5 Specific Gravity 2.85 to 3.35 Fracture Sub-Conchoidal Inclusions in Tourmaline The thread of fiber-like capillaries often plaited in a net-like pattern. Angular, thin-film mirror-like inclusions. Tube-like two-phase inclusions running parallel to crystal’s length: may create chatoyancy. Flat, film-like liquid inclusions, needle-like mineral inclusions, parallel oriented hollow tubes. Tourmaline Treatments By heating to (450 - 650 degrees C), color changes can be produced in some tourmalines. Some green tourmaline becomes emerald green; others are lightened. The color of tourmalines that have been changed with gamma-irradiation may fade. Coatings on tourmaline give a wide range of options for color, iridescence, and other appearance factors. The coating is shallow and can be easily damaged without proper handling. Crystallography of Tourmaline: Crystal System Trigonal Habit Prismatic to acicular crystals Rough Tour