Tourmaline


Tourmaline is the most colorful of all gemstones. It occurs in all colors, but pink, red, green, blue and multicolored are its most well-known gem colors. Scientifically, tourmaline is not a single mineral, but a group of minerals related in their physical and chemical properties. The mineral Elbaite is the member of the Tourmaline group that is responsible for almost all the gem varieties. Three other members of the group - Schorl, Dravite and Liddicoatite, are seldom used as gemstones.

The name tourmaline comes from the Singhalese words 'tura mali'. In translation, this means something like 'stone with mixed colours', referring to the colour spectrum of this gemstone, which outdoes that of all other precious stones. There are tourmalines from red to green and from blue to yellow.
There are tourmalines which change their colour when the light changes from daylight to artificial light, and some show the light effect of a cat's eye. No two tourmalines are exactly alike. This gemstone has an endless number of faces, and for that reason it suits all moods. No wonder that magical powers have been attributed to it since ancient times. In particular, it is the gemstone of love and of friendship, and is said to render them firm and long-lasting.

Color White, Colorless, Blue, Red, Green, Yellow, Orange, Brown, Pink, Purple, Gray, Black, Multicolored
Hardness 7 - 7.5
Refractive Index 1.616 - 1.650
SG 2.9 - 3.3
Double Refraction .018
Luster Vitreous
Mineral Class Tourmaline

USES

Tourmaline of all colors are faceted into gems for jewelry, but the red, green, blue, and multicolored stones, especially watermelon, are the most popular. Tourmaline can be found in fairly large transparent crystals, and these can produce very large exquisite and flawless gemstones. Tourmaline is used as a large pendant stone, in bracelets, rings, and earrings. Lesser quality stones are cut into cabochons, and are also polished into beads and used in bracelets and necklaces.  Pink and green Tourmalines from certain localities contain tiny, parallel inclusions, causing them to display a strong cat's eye effect when polished. Such stones are often cut as cabochons and called "Cats' Eye Tourmaline" . Some pink, green, and multicolored Tourmalines are also carved into ornamental figures and carvings.

VARITIES

  • Achroite  -   Colorless variety of Tourmaline.

  • Canary Tourmaline  -  Bright yellow Tourmaline from a recent deposit in Malawi.
  • Cat's Eye Tourmaline  -   Tourmaline displaying a cat's eye effect.

  • Chrome Tourmaline  -  Tourmaline with a deep green color caused by chromium impuritiess.
  • Dravite  -   Brown variety of Tourmaline. See the mineral Dravite for additional information.

  • Elbaite  -  Individual member mineral of the Tourmaline group, and the Tourmaline form responsible for almost all Tourmaline gemstones. In the gem industry, the term Elbaite often connotes the green form, and occasionally the multicolored form. See the mineral Elbaite for additional information.
  • Indicolite  -   Light to dark blue variety of Tourmaline.

  • Paraiba Tourmaline  -  Neon blue, highly desirable variety of Tourmaline that originated in Paraiba, Brazil. Its interesting color is caused by inclusions of copper. Although technically the term describes only those Tourmalines from Paraiba in Brazil, the gem trade now uses it to describe any light to neon blue Tourmaline from any worldwide location.
  • Rubellite  -   Pink to red variety of Tourmaline.

  • Schorl  -  Black form of Tourmaline. See the mineral Schorl for additional information.
  • Siberite  -   Occasionally used to describe purple Tourmaline.

  • Verdelite  -  Occasionally used to describe green Tourmaline.
  • Watermelon Tourmaline  -   Multicolored Tourmaline with a red center, surrounded by a green outer layer (or vice versa). Watermelon gemstones are multicolored red and green.
TOURMALINE TREATMENTS AND ENHANCMENT

Heat treatment can enhance the color of some Tourmalines. Some greenish stones can be made deep green, some brownish-red stones can be made red, and some light pink stones can be made colorless through heating. The color of some light colored stones can also be made into a deeper hue, and dark, transparent Dravite can be made lighter.

TOURMALINE SOURCES

Important deposits of Tourmaline are in Afghanistan, Pakistan, Russia, Burma (Myanmar), and the United States (California and Maine). Several African countries have recently become big producers of gem Tourmaline, specifically Madagascar, Namibia, Mozambique, Tanzania, Nigeria, and Malawi.

Tourmaline is a very special family of gemstones: it is one of the only gemstones in the world that occurs naturally in every color, sometimes even containing two colors in one stone.  Ancient Egyptians believed that the tourmaline passed through a rainbow on its way up through earth, and thus was blessed with all the colors.
Certain kinds of tourmaline are very rare and expensive, such as the Paraiba tourmaline found in Brazil, while others are common and affordable.


The Family of tourmalines:
Rubelite
Rubelites are the tourmalines that come in very saturated colors of hot pink, magenta and red. Fine rubelites are among the most prized tourmalines.
pink tourmaline
Pink Tourmaline
Pinks that are too pale to be rubelite are simply called pink tourmalines.
  pink tourmaline
Orange Tourmaline
Orange tourmaline is very unusual and rare, but it does exist.  The most common hues tend toward peach.  Orange tourmaline gemstones will usually have overtones of either yellow, pink or brown.

peach tourmaline   
Yellow tourmaline
Pure, saturated yellow tourmaline is very rare.  It is sometimes called "Canary tourmaline." More common hues are pale yellow and greenish yellow.
yellow tourmalineyellow tourmaline
Green Tourmaline
Green tourmaline is one of the most common colors for this gemstone.  The most typical color is a dark, forest green. Though green tourmalines are reletavily inexpensive, when the green is caused by chrome, the color becomes a rich emerald green and is quite valuable.
green

Paraiba Tourmaline
Paraiba tourmalines are named after the region of Brazil where they are found and mined.  They are famous and extremely valuable for their electric hues of teal, aqua and blue.  These are some of the most valuable stones in the world today.
paraiba tourmalinegarnet

Indicolite
These are the tourmaline gemstones that are a pure, traditional blue.  They tend to be a cool, greenish blue and are more often dark than pale.
pink tourmalineindicoliteindicolite
Purple tourmaline
A purely purple tourmaline is pretty much unheard of.  Rubelites can have lilac shades, but until recently truly purple was not one of the colors available in tourmaline.  A small and rare deposit was found a few years ago in Mozambique.  Many of these stones are heat treated to turn them electric teal and sell as "Paraiba."  They are mostly stones for collectors and connisseurs. 
purple tourmalinepurple tourmaline

Black Tourmaline
This is one of the most common colors of tourmaline.  Very large specimen pieces (2" -3") are commonly available.  However, it is rarely transparent and is not often used as a gem. 
black blackblack


Colorless Tourmaline
Colorless or "white" tourmaline is also available.  It is rare to find them, but they are not too expensive.  Since the most prized feature of tourmalines is their rich colors, the colorless variety is really only popular with collectors. 


Bi-Color Tourmaline
One of the special characteristics of tourmaline is its wide color range.  Another is its pleochroism.  These two characteristics make it possible for tourmaline gemstones to contain two (or even 3) colors in one single gemstone. 
watermelonbi-colorpink tourmaline


Watermelon Tourmaline
Bi-color tourmalines in which one color is green and the other is pink or red are called "watermelon tourmalines".  These are very popular and revered by gemstone and jewelry connisseurs.  They are used both faceted and scliced.

tourmaline tourmaline





The Most Valuable Tourmaline

The most valuable tourmaline is large (over 3 carats), perfectly clear and perfectly cut, and most importantly, containing an intense, rare color.

Lowest Value: This tourmaline cabochon has very poor clarity and very dull, dark color.  Its one redeeming feature is its large size. (over 7 carats) Low Value: These beads have  very nice, strong attractive colors.  However, their poor clarity and small size detract from their value considerably. Medium Value: This peice of tourmaline is very clear, well cut and with a lovely intense color.  It is not exceptionally valuable because green is a very common color of tourmaline and is therefore, not very high priced.  High Value:  This tourmaline is perfectly clear, well cut and has a bright intense beautiful pink color.  This color of tourmaline is quite rare.



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