History & Introduction

Tourmaline is the gemmological name given to the complex gem-quality of silicate minerals. It is available in the vivid colors of rainbow. Due to this wide range of color availability, tourmaline is considered to be one of the versatile gemstones found today in the market. Tourmaline is derived from the Sinhalese word, "turamali", which means "stone with various colors."

Around 1500s tourmaline was first thought to be used as a gemstone, however distinct mineral species were not actually described until the 1800s. Green tourmaline was actually introduced in 1875 by George Kunz, an American mineral collector, from the Mount Mica mine in Maine and sparked the popularity on the mainstream jewelry market.

Schorl, dravite, uvite, liddicoatite and elbaite are the primary species of tourmaline. Schorl is the most common variety, making up nearly 95% of all tourmaline deposits, however not frequently it is desired as a gemstone. Chiefly the tourmaline gemstones comes from of the elbaite family. As tourmaline possess a huge collection of correlated gemstones, mainly tourmaline is traded under very color-specific varietal names. Famous trade names of tourmaline are pink-red 'rubellite', blue-green 'Paraiba', blue 'indicolite' and multicolored 'watermelon tourmaline'. Lesser-known trade names include colorless 'achroite', green 'verdelite' and 'chrome tourmaline'. Descriptive names for tourmaline such as 'yellow tourmaline' or 'pink tourmaline' are also commonly used to market the fancy-colored tourmaline gemstones.

Properties - Tourmaline is famous in showing exclusive pyro-piezoelectric characteristics that means crystals can produce and hold an electrical charge when they are hold to mechanical stress, extreme temperature fluctuations or pressure, earning it the nickname of the 'electric stone'. The rubbing of tourmaline crystals cause static and when it is held over dust or ash. This static attracts particles, which is why at times it referred as the 'Ceylonese (Sri Lankan) magnet'.

Availability - Tourmaline is available in pegmatites and alluvial deposits across the globe. The United States was considered the primary source for fine tourmaline. Currently important tourmaline deposits are from Minas Gerais and Bahia, Brazil. Other prominent tourmaline sources are Afghanistan, Australia, Nigeria, Malawi, Burma (Myanmar), Italy, (Elba) Madagascar, India, Mozambique, Namibia, Nepal, Pakistan, Russia, Switzerland, (Tessin) Zaire, Tanzania, Sri Lanka, the United States (California and Maine), Zambia and Zimbabwe.

Tanzania is popular in producing the fine emerald-green chrome dravite tourmaline, in late 1990s, a copper-bearing blue Paraiba tourmaline was discovered in Nigeria; soon, then, another deposit of a copper-bearing Paraiba tourmaline was found in Mozambique. Africa's Paraiba tourmaline deposits were not brightly colored like the Brazilian materials. Zambia is popular to have fine red rubellite and yellow canary tourmaline, whereas Afghanistan is famous to have deposits of producing fine green verdelite and rare blue indicolite

Buying Guide

Lately, tourmaline has become one of the famous color gemstones. Due to its wide variety of colors new buyers are attracted by its huge choice of colors and its very good gemstone characteristics -- it is practically hard as well durable enough for every type of jewelry. It is an affordable gemstone.

Before you go to buy a tourmaline from the market it is better to read a guide and know about the stone. So that you are able to buy a correct and that too in a right amount.

In recent years tourmaline has become one of the most popular of all colored gemstones. Due to the huge choice of colors the buyers new to tourmaline get attracted and in fact a very good gemstone with properties like practically hard, and durable enough for every type of jewelry. It is still a very reasonably priced gemstone too, particularly in larger sizes, since per carat price for tourmaline doesn't increase radically like the prices for larger sapphire and ruby.

However, there are some important differences between varieties of tourmaline, and some colors are rarer and thus more expensive. This short buying guide will assist you to know the quality and price grades in the current tourmaline market.

Tourmaline is one of the few gemstone where ranges of bi-color and tri-color specimens is seen. These occur in all colors, but the most coveted color is the watermelon tourmaline, known for its green and pink/red bands. Highest examples are greatly regarded by collectors.

It is fair to describe that the famous tourmaline colors are green and pink. In every shade of pink the tourmaline is available from the softest pink to intense hot pink. The green tourmaline is known for the excellent clarity as well as a wide variety of color from blue/green to forest green to mint. Green tourmaline is frequently found in huge sizes at genuine cost.

Cut and Shape - Tourmaline is often cut into long rectangular bar shapes because of its elongated crystal habit. However, the gemstone is also available in various traditional and fancy shapes and a range of cutting styles. Because of the strong pleochroism of tourmaline, lighter colored tourmaline is typically oriented with the table facet perpendicular to the main axis, in order to present the richest hue. However in general darker stones are usually cut with the table parallel to the main axis. Watermelon tourmaline is often cut into slices to best exhibit its characteristic and attractive color zoning.

Treatment - Tourmaline is very rarely treated. However, some stones may be heated to improve color and clarity. Yellow, pink and red varieties of tourmaline may be irradiated to enhance color, although irradiation is nearly impossible to detect and does not normally affect value.

Gemological Characteristics:

Chemical Formula	Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH) Elbaite: Na(Li1.5,Al1.5)Al6Si6O18(BO3)3(OH)4 Dravite: - NaMg3Al6Si6O18 (BO3)3(OH) 4 Liddicoatite: - Ca(Li2Al)Al6Si6O18(BO3)3(OH)3F Chrome dravite: - NaMg3Cr6Si6O18 (BO3)3(OH) 4
Crystal Structure	Trigonal; long crystals with a triangular cross-section and sides are round, definite striation parallel to axis
Color	Available in every colors
Hardness	7 to 7.5
Refractive Index	1.614 to 1.666
Density	2.82 to 3.32
Cleavage	Blurry
Transparency	From transparent to opaque
Double Refraction or Birefringence	0.014 to -0.032
Lustre	Vitreous
Fluorescence	Not so strong or unavailable

Classification:

• Green tourmaline
• Pink tourmaline
• Blue tourmaline
• Multi tourmaline
• Watermelon tourmaline