McAfee SECURE sites help keep you safe from identity theft, credit card fraud, spyware, spam, viruses and online scams

Home » Minerals » Tourmaline

Tourmaline


Mineral Properties and Uses



Physical Properties of Tourmaline

Chemical Classification silicate
Color bluish black, black, yellow, pink, blue, green, colorless, red
Streak colorless, gray
Luster vitreous
Diaphaneity transparent to nearly opaque
Cleavage poor
Mohs Hardness 7 to 7.5
Specific Gravity 3 to 3.3
Diagnostic Properties lack of cleavage, color
Chemical Composition (Ca,K,Na,[])(Al,Fe,Li,Mg,Mn)3(Al,Cr, Fe,V)6
(BO3)3(Si,Al,B)6O18(OH,F)4
Crystal System hexagonal
Uses gemstone


Tourmaline beads
The variety in tourmaliine color is shown with this strand of beads.


Tourmaline cabs
Numerous cabochons of tourmaline from Africa. Each gem is approximately 6 millimeters by 4 millimeters.


Tourmaline gemstone
A cut piece of tourmaline. The gemstone is approximately 1.8 carats, and 9 millimeters by 7 millimeters.


Tourmaline teardrop cab
A teardrop cabochon of tourmaline from San Diego, California. The gemstone is approximately 1.4 carats, and 9 millimeters by 5 millimeters.



Find it on Geology.com




More from Geology.com


Gemstones
Gemstones: Fantastic images and articles about colored stones and diamonds.
volcanic explosivity index
Volcanic Explosivity: Learn about some of the most explosive volcanic eruptions.
Sliding Rocks
Sliding Rocks Mystery: What causes these rocks to slide across a Death Valley playa?
oil fields at night
Oil from Space at Night These night views of Earth show oil field illumination and gas flaring.
Oil and Gas
Oil and Gas: Articles about oil and natural gas in the US and around the world.
gem photos
Colored Stones: A colorful collection of gemstones from around the world!
Fossils
Fossils: Learn about fossils and fossil discoveries around the world.
Helium
Helium is a byproduct of the natural gas industry. Its most important use is in MRI.


Tourmaline in granite
Tourmaline in granite from Stoneham, Maine. Specimen is approximately 5 inches (12.7 centimeters) across.




Tourmaline
A close-up of tourmaline from Pierrepont, New York. The overall specimen is approximately 4 inches (10 centimeters) across.


Tourmaline from NY
Tourmaline from Pierrepont, New York. Specimen is approximately 3 inches (7.6 centimeters) across.


Tourmaline in microcline
Tourmaline in microcline from Bathurst, Ontario, Canada. Specimen is approximately 3 inches (7.6 centimeters) across.


Mineral Information
 Andalusite
 Anhydrite
 Apatite
 Arsenopyrite
 Augite
 Azurite

 Barite
 Bauxite
 Beryl
 Biotite
 Bornite

 Calcite
 Cassiterite
 Chalcocite
 Chalcopyrite
 Chlorite
 Chromite
 Chrysoberyl
 Cinnabar
 Clinozoisite
 Copper
 Cordierite
 Corundum
 Cuprite
 Diamond
 Diopside
 Dolomite

 Enstatite
 Epidote

 Fluorite

 Galena
 Garnet
 Glauconite
 Gold
 Graphite
 Gypsum

 Halite
 Hematite
 Hornblende

 Ilmenite

 Jadeite

 Kyanite
 Limonite

 Magnesite
 Magnetite
 Malachite
 Marcasite
 Molybdenite
 Monazite
 Muscovite

 Nepheline
 Nephrite

 Olivine
 Orthoclase

 Plagioclase
 Prehnite
 Pyrite
 Pyrophyllite
 Pyrrhotite

 Quartz

 Rhodochrosite
 Rhodonite
 Rutile
 Scapolite
 Serpentine
 Siderite
 Sillimanite
 Silver
 Sodalite
 Sphalerite
 Spinel
 Spodumene
 Staurolite
 Sulfur
 Sylvite

 Talc
 Titanite
 Topaz
 Tourmaline
 Turquoise

 Uraninite

 Witherite
 Wollastonite

 Zircon
 Zoisite


What is a Debris Flow?
Rock Type Photo Gallery
Blood Diamonds
Volcanoes!
Teaching Plate Tectonics with Drawings
Mineral Rights
Diamonds Don't Form From Coal
San Andreas Fault




© 2005-2014 Geology.com. All Rights Reserved.
Images, code and content of this website are property of Geology.com. Use without permission is prohibited. Pages on this site are protected by Copyscape.