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Tourmaline Buyer's Guide

Tourmaline, a perennial favorite of the gem world has long been one of the most consistently popular gem types available. Although not as glamorous as ruby, sapphire or emerald, in reality the beauty of tourmaline and the value of certain tourmaline types means they can be as every bit as precious.

A bright, clean gem that comes in a kaleidoscopic assortment of colors, tourmaline's name derives from the Sri-Lankan Sinhalese language word "turmali", meaning "mixed" - and with the exception of quartz-based gems, tourmaline must be the most diversely colored gem type in the world. Its diversity of color also includes color zonings, whereby concentric or attractive line patterns of two or three different colors within one gem are frequently seen. Other diverse effects that add beauty and value to tourmaline are phenomena such as cat's eyes and color change.

With the depth and diversity of colors and effects seen in the tourmaline family, novices to the arcane world of gems can find the species as a whole comparatively hard to understand compared to less diverse gem types. Beauty, color, rarity, size, optical effects, patterns, market demands and more must all be accounted for.


As mentioned above, tourmaline occurs in every color of the rainbow, and within these, multiple combinations of colors also occur in single gems. Many tourmalines have been given specific names that are used when discussing the gem. Sometimes these named varieties are treated as a gem type within their own right. Briefly, the most commonly attributed names to the different tourmaline colors are:

  • Rubellite tourmaline - Red tourmaline
  • Verdite tourmaline - Green tourmaline
  • Indicolite tourmaline - Blue tourmaline
  • Dravite tourmaline - Brown and Cognac tourmaline
  • Achroite tourmaline - Colorless tourmaline
  • Schorl tourmaline - Black tourmaline
  • Paraiba tourmaline - Bright neon blue-green tourmaline from Paraiba, Brazil
  • Watermelon tourmaline - Red or pink tourmaline surrounded by a green rind that resembles the cross section of a watermelon
  • Chrome tourmaline - Bright green tourmaline colored by chromium


The proper lighting conditions for tourmaline will depend on the color variety. Reds, oranges and yellows generally look best under incandescent light, while greens, blues and violets appear prettier under daylight. When buying any gem, it is always a good idea to examine it under a variety of light sources, to eliminate future surprises.


Different varieties of tourmaline tend to have different clarities. Thus while large clean tourmalines in the blue and blue-green colors are available, almost all red and pink tourmalines will show eye-visible inclusions. The most common inclusions in tourmaline are fractures and liquid-filled healed fractures. Needle inclusions are also common.

Shape & Cut

Faceted tourmalines (those with flat polished faces) are found in a variety of shapes and styles. Due to the prevalent long acicular crystal shapes of tourmaline, emerald cuts and fairly elongated emerald cuts are commonly seen. Ovals and cushion cuts are common, as well as other shapes such as emerald cuts and hearts shapes.

A perfectly cut tourmaline should always exhibit good symmetry and polish conditions, facets should be aligned straight in relation to the gem’s girdle, and also to each other. Polish conditions should be good with no visible surface pits or polishing lines.

Cabochon cuts are most commonly applied to those tourmalines whose clarity is not ideal for faceting. However, they are also used to develop and display cat’s eyes in chatoyant tourmaline. Well-cut and proportioned cabochons with good symmetry, which are semi-transparent with smooth un-cracked domes, are the ideal.

Stone Sizes

Paraíba tourmalines are extremely rare in faceted stones above 2 cts. Fine Paraíba above 5 carats can be considered world-class pieces. Most stones tend to be less than 1 ct. Chrome tourmalines of quality are rare in sizes above 10 cts., as are rubellites.


Tourmaline is a pegmatite mineral and so is mined from the world’s great pegmatite districts. Foremost is Brazil, but fine tourmalines are also found in San Diego County, including the famous Pala pegmatite district, and Maine. The East African countries of Kenya, Tanzania, Mozambique and Madagascar have also produced fine tourmaline in the past. Beautiful yellow “canary” tourmalines come from Malawi, while extremely fine rubellites and blue-green tourmalines are found in Nigeria. Afghanistan, Sri Lanka and Burma also produce gem tourmalines on occasion.

Carat Weight

Tourmaline frequently occurs in large crystal sizes and such large specimens can be thought of as being fairly accessible. Large crystal sizes also help to enhance tourmaline's perceived depth and richness of color.

Similar to most other gems, when the carat weight of a tourmaline increases, so does the price per carat. However, large tourmaline crystals with their abundant occurrence rates are simply more plentiful than in habitually smaller gems such as ruby and sapphire. This means that weight related price jumps in tourmaline are less severe than in ruby and sapphire. Indeed, it is not uncommon for comparable quality 3 Carat, 4 Carat, and 6 Carat tourmalines all to have the same or very similar per carat prices – something that is unthinkable regarding diamond, ruby and sapphire.

The Use Of Heat

Many tourmalines seen on the market today have been subjected to high temperatures in an age-old practice that is said to have originated in Sri Lanka some 2,000 years ago. They are heated at high temperatures to improve their clarity and to intensify their colors. However, there are also many tourmalines on the market are not heated. Unusually, the market makes little or no distinction at all between the heated and non-heated specimens.

Properties of Tourmaline


Tourmaline is one of the most complex of all mineral groups, and includes the following species:
  • Buergerite: NaFe3+3Al6(BO3)3Si6O18(O)3(OH)
  • Chromdravite NaMg3[Cr,Fe3+]6(BO3)3Si6O18(OH)4
  • Dravite: NaMg3Al6(BO3)3Si6O18(OH)4
  • Elbaite: Na(Li1.5Al1.5)Al6(BO3)3Si6O18(OH)4
  • Feruvite: CaFe2+3[Al5Mg](BO3)3Si6O18(OH)4
  • Foitite: [Fe2+2(Al,Fe3+)]Al6(BO3)3Si6O18(OH)4
  • Liddicoatite: Ca(Li2Al)Al6(BO3)3Si6O18(OH)4
  • Magnesiofoitite: [Mg2+2(Al3+)]Al6(BO3)3Si6O18(OH)4
  • Olenite: NaAl3Al6(BO3)3Si6O18(O)3(OH)
  • Povondraite: NaFe3+3Fe3+6(BO3)3Si6O18(O)3(OH)
  • Rossmanite: (LiAl2)Al6(BO3)3Si6O18(OH)4
  • Schorl: NaFe2+3Al6(BO3)3Si6O18(OH)4
  • Uvite: CaMg3[Al5Mg](BO3)3Si6O18(OH)

In summary, tourmaline is a complex aluminum boro-silicate, with heavy emphasis on the “complex.” One pundit likened it more to a medieval alchemist’s brew than a respectable mineral species. And a glance at the above formulae would bear that out.

Hardness (Mohs)

Specific Gravity

Refractive Index

Crystal System


7 to 7.5

3.06 (+ 0.20; - 0.06)

1.624–1.644 (0.18–0.40; usually 0.20, may be greater in dark stones); doubly refractive, uniaxial negative

Hexagonal (trigonal)

Any and all. Tourmaline occurs in more colors than any other gem. Some colors have specific variety names, including:

  • Bi-color: More than one color in the same stone
  • Chrome: Intense green, colored by chromium and/or vanadium
  • Indicolite: Blue
  • Paraíba: Electric blue to green, colored by copper
  • Rubellite: Red
  • Watermelon: Pink in the center, green at the edge




Strongly dichroic with the ordinary ray having a darker color


Cat's eye tourmalines are common. Color-change chrome tourmalines, which change from green to red, are occasionally found.


Ultrasonic: generally safe, but risky if the gem contains liquid inclusions
Steamer: not safe
The best way to care for tourmaline is to clean it with warm, soapy water. Avoid exposing it to heat or acids.

A variety of enhancements are regularly applied to tourmaline, depending on the source and variety. These include heat, irradiation, and oiling.

Synthetic available? No



Synthetic available?
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