Tourmaline Stone

1Tourmaline Value – Are Tourmaline STONES Expensive?

Tourmaline stone is a family of related minerals with varying properties. The gems make for popular jewelry thanks to their great variety of colors tourmaline.

Fine Tourmaline can be found in a range of colors and varieties, ranging from colorless to pink tourmaline and all the way to black tourmaline, with amazing varieties such as Paraiba tourmaline Gems and watermelon tourmalines.

Because of the great variety of tourmaline gems, not all of them have the same value. Some varieties and colors are rarer and therefore more desirable, while others are inexpensive.

One of the rarest and most tourmaline stone, is the Paraiba Tourmaline, which is discussed further on in this article. It has a limited supply and high demand, making the price for these gems exceptionally high.

Chrome Tourmaline is another valuable variety. The gem is colored by chromium and vanadium and displays a rich green color, comparable to Colombian Emeralds and Tsavorite Garnets.

At the cheaper end of the scale, you can find Black Tourmaline, the most common and cheapest of the tourmaline gemstone varieties. Because its characteristics are the same as the other gemstones in the family, black tourmaline is excellent value for money.

Other common colors of tourmaline stone are yellow-green, brown, and orange tourmaline. Tourmaline Stones with intense color and excellent clarity will fetch higher prices, as with any other gem. Pink Tourmalines often demands a higher price tag, especially the Hot Pink variety. The same can be said for bi-color and tri-color stone. Watermelon Tourmaline is incredibly popular due its combination of red, green, and sometimes white, bands in the same gem.

As with all gemstones, their value is based on the 4 C’s, which are Color, Clarity, Cut, and Carat (weight), and tourmaline is no exception to these quality factors.

Color

Amongst the most popular and sought-after colors, are the red/pink variety of tourmaline, known as rubellite tormaline because of their resemblance to rubies.

Green Tourmaline are an alternative to the deep and rich hues of Emeralds or the softer greens of Peridot, because of their stunning pastel hues. The highest quality green tourmalines are transparent, clean, and brilliant with beautiful bluish-green hues. Many green varieties of the stone are highly pleochroic, meaning that their color changes depending on the angle of the light and the angle of the gemstone. The gemstone that show bright green at one angle and blue green from another are the most valuable and desired pleochroic black tourmaline.

Chrome Tourmalines offer hues with higher saturation levels than most green tourmalines. These stones can be a cheaper alternative to Tsavorite or Emeralds, which are both rare to find in sizes over 2-carats. Meanwhile, finding larger chrome black tourmaline is rather common, as they are found in sizes up to 5-carats. While the tourmaline gem cannot match tsavorite in luster or brilliance, it is far cheaper than a tsavorite of the same size and quality.

The more common tourmalines on the market are dark-toned stone, but they aren’t as attractive as other varieties and colors. Some of these gems absorb light intensely from certain angles, making them appear completely black. Cutters will often fashion these stone with a table parallel to the length of the crystal. When a crystal is cut in this way, it might show a brownish or yellowish color through the crown. Dealers will often describe these gems as ‘oily’ or ‘olive’ green. However, their price tag is much lower than fine blue green tourmaline or brighter blue green stone.

Blue Tourmaline has a wide range of tones, from light to dark. However, the hue is often modified by green to give the stone a blue color with a hint of green modifying color or a more greenish color, while still being blue. There are also tourmalines with an equal amount of blue and green in their color. Like green tourmalines, blue stone can show a vivid color or a less saturated color, appearing grayish.

Paraiba Tourmalines are also blue in color, with a variety of different tones and hues, although blue and violet have the most appeal amongst buyers. While dealers name them a variety of ways to catch the attention of potential buyers.

The prices for Paraiba tourmalines are above other tourmaline due to being more attractive, having higher color saturation and being rarer than other tourmalines. They can easily be distinguished from most other tourmaline because of their brighter hues, lighter tones, and more saturated hues.

Bicolor, multicolor, and Watermelon tourmaline color zoning happens when the elements which make the stone change in concentration or composition during the formation of the crystal. Stones which show this property are often cut to showcase their exotic color combination. Gemologist call these tourmalines Parti-Colored.

You can also find tourmalines that are color-zoned the whole length of the crystal. For example, a crystal that starts of pink at one end, but is green at the other. The color zoning may also be parallel to the length of the stone, such is the case of Watermelon Tourmalines. They are given this name because the crystals have a color scheme that resembles the flesh and the rind of the fruit which gave them their name. It is not uncommon for designers and jewelers alike to exploit the watermelon colors and cut the tourmaline crystal into slices, rather than faceting a rough stone.

Clarity

Tourmaline Crystals grow in environments rich in liquids, and it is not uncommon for some of those liquids to be captured inside the crystal during its growth and produce inclusions. The most common inclusions are needle-like cavities that run parallel to the length of the stone. Under magnification, it is possible to see that they are filled with liquid or bubbles. Another common inclusion are growth tubes – these are hollow tubes often capped by minute mineral crystals. If there are enough of these inclusions and the rough is cut correctly, it can form a cat’s eye.

Dealers and collectors tend to tolerate red tourmalines with some eye-visible inclusions, so long as their color is vivid and attractive. Inclusion that reach the surface hamper polishing and will make gems difficult to sell. While liquid inclusions in stone of intense color are less visible, any stone with a prominent white inclusion, regardless of its color, is completely undesirable.

In lighter toned gems with low saturation, inclusions are more visible, and because they don’t have the vivid colors to compensate for these inclusions, most buyers won’t accept the stones with eye-visible inclusions. Even if these gems are cut as cabochons, a cut used to emphasize color and minimize eye-visible inclusions.

Red and Pink tourmaline are more commonly accepted with inclusions, unless their size or the number of inclusions makes them less desirable. Knowledgeable collectors and consumers consider color to be the most dominant value factor. Green tourmalines, on the other hand, are expected to be completely free of eye-visible inclusions. For the other colors of tourmaline, those with no eye-visible inclusions have a higher value, as any visible inclusions considerable drop the value of the gemstone.

Cut

Many Tourmaline crystals have elongated shapes, which has a direct impact on the shape and proportions of a finished gem. Consequently, there are many narrow, non-standard sizes available on the market. While they are still very attractive, gem buyers prefer gemstones with standard sizes, as they are easier to set in standard mountings.

Tourmaline are often cut into long rectangles. Cutters will make the cut parallel to the length of the rough stone to reduce waste. However, expert cutters will also take into consideration the optical properties of tourmaline.

Tourmaline are pleochroic stone. This means that the stone can show different colors depending on the angle of the stone and the reflecting light. One of tourmaline’s pleochroic colors is typically much darker than the others. Furthermore, tourmaline crystals absorb the light along the length of the stone, rather than across it. Therefore, a stone will appear pale green across the length, but a much darker, almost black color when looked down its length.

Many cutters will orient a gem based on the depth of its color, rather than cutting each stone lengthwise. To darken a pale rough, they can cut a gem’s table perpendicularly to its length. And to lighten a dark rough, they would orient the gem’s table, so it is parallel to its length.

CARAT (Weight)

Larger fashioned tourmaline stones are considerably more expensive, as the larger the stone, the larger the per-carat price. While some examples of tourmaline can reach extraordinary sizes, these are extremely rare. facet-quality rough material is less available and therefore more expensive. For finished gemstones of similar color and clarity, the price per-carat tends to raise once the gems pass 5-carats.

2Tourmaline colors

Tourmaline can be found in a variety of colors, from colorless to black tourmaline. The crystals are often color-zoned along their length (bicolor, tricolor, particolor, etc.) or concentrated in zones (watermelon tourmaline).

3Identifying Characteristics

Because the physical properties of some tourmaline species are so close that separating them is difficult, it is easier, for gemological purposes, to identify them all under the same umbrella term: Tourmaline.

Separating different stones apart and into specific species of tourmaline may often require advanced gemological tests.

One interesting fact about the stone is that they are both Piezoelectric and Pyroelectric. This means the generate electricity when under pressure and heated, and also produce an electrostatic charge when rubbed.

4TradeNames

Tourmaline gemstones have many trade names, based on their color, and looks. Many stones have similar characteristics to specific species but are not species names. This include Rubellites which are usually Elbaites but can also be Liddicoatites or Olenites. Paraiba tourmalines were long believed to be elbaites until 2017 when copper-bearing liddicoatites with the same colors where discovered.

Dravite is an official species that change, but is sometimes given to yellow and brown tourmalines, regardless of what species they belong to.

Paraiba Tourmalines

Paraiba Tourmalines are colored by copper. They were originally named after the state they were first discovered, Paraiba, in Brazil, although they have made recent discoveries in Nigeria and Mozambique.

Paraiba tourmaline has a brief history, but during that time, dealers have accepted its scarcity and the price of the gem. However, the recent discoveries of similar gems in eastern Africa present the market with new opportunities, such as the possibility of viable commercial sources of the rare, copper-bearing tourmaline. These sources could, one day, supply the industry with more gems. Unfortunately, with new sources being found outside of the Paraiba State in Brazil, it does force us to question about the term Paraiba and if it has rights reserved to name these rare and valuable tourmalines.

The definition of Paraiba Tourmaline is color and copper content, even if some dealers only reserve the name for stones found in Brazil. Identifying these stones requires quantitative chemical analysis testing.

Paraiba was first discovered in the late 1980’s, and ever since then the beautiful neon blues and greens of this stone have shaken the gemstone world. The gemstone’s unique and vivid coloring instantly set it on a different level to other tourmalines. The initial worldwide reception was almost chaotic, especially in Japan, as the Japanese are renowned for their demand for fine-colored and high-quality gems.

Prices for the newcomer quickly surpassed the $10,000 mark, especially for high-quality stone between 3 and 5-carats. No tourmaline – not even the highest quality Rubellite or Chrome Green Tourmaline – had ever achieved those prices. It is without question that the rarity of Paraiba also influences the price of the gem.

Paraiba is an Elbaite Tourmaline [ Na(Li1.5,Al1.5)Al6Si6O18(BO3)3(OH)3F ] , originally found in one area in the state of Paraíba, Brazil, in the northeast corner of the country. Like many other Brazilian elbaites, it forms in pegmatite. Researchers believe that Paraiba tourmalines are formed under very unusual circumstances, with large amounts of manganese and copper found in its elements, which give the stone its color. This makes Paraiba even more unusual, because, while copper can color other gems, such as turquoise, it is not found as a coloring agent in any other type of tourmaline.

In some examples of the gem, there is so much copper that inclusions of native copper – almost pure metal inclusions – strike the gem’s interior. Experts speculate that these inclusions took form during the early stages of cooling, after the gem had begun to crystallize.

Because Paraiba rough has such a high value, they are almost always custom cut. They are often faceted into brilliant cuts, such as pear and oval shapes. Paraiba stones are rarely larger than one carat. However, the key value factor for these stones is color and not size. If a dealer is given a choice between a larger stone or a better colored one, with all the other factors being the same, the dealer will choose the gem with a better color.

Tourmalines with similar color not caused by copper are known as indicolites.

Rubellites

The name Rubellite refers to tourmaline with Ruby-like colors, from saturated dark tourmaline pink, to red colors with medium to dark tones. Their color is normally a strong purplish, orangish or brownish red.

Watermelon Tourmalines

Watermelon Tourmalines have a pink or red ‘core’ with a green ‘rind’ surrounding it. Some examples will have white rings between the two colors. They are aptly named because when cut, the stone resembles a slice of watermelon.

5Sources

There are many sources for tourmaline gemstones. Many sources produce more than one variety of the stone and there are also sources that are not listed here, as these are the main locations for tourmaline.

The four largest sources of tourmaline stone are Brazil (especially for Paraiba, black tourmaline and pink tourmaline), Kenya, Madagascar, and the United States (with the largest sources here being California, Connecticut, Maine and New York & New Jersey).

Other sources for pink tourmaline and green tourmaline gemstones include Afghanistan, Bolivia, Czech Republic, India, Japan, Mexico, Mozambique, Myanmar, Namibia, New Zealand, Nigeria, Russia, Scotland, Sri Lanka, Tanzania, Zambia, Zimbabwe

Black tourmaline crystals are mostly found in Africa, and Sri Lanka, and they are considered the cheapest form for industrial use-case or change of form into powder for electronics.

6Care & Who can Wear Tourmaline Stone

Even experienced gem cutters will find a challenge with rough pink tourmaline. Multi-colored gemstones are often weak at the point where the color meet, but every variety may have stressed zones. Once the tourmaline rough is cut and set, it makes for durable tourmaline jewelry.

It has a Mohs hardness of 7 to 7.5, meaning it can resist scratches from everyday hazards, including household dust. This means anyone can wear a tourmaline gem for any occasion. Because of their electric conducting properties, tourmalines will attract more dust than other non-conductive gems, therefore their hardness is a point to their advantage. But this tendency to attract more dust also means they will need more frequent cleaning.

Because most tourmalines have several inclusions, you must avoid ultrasonic cleaning or using steam devices to avoid change in the gemstone. The vibrations and heat can cause liquid inclusions to expand and shatter the stone. The best way to clean your gemstone is with a soft brush, and warm soapy water, using a mild detergent.

7Chemical Composition Table

Tourmaline Mineral Composition

  • Adachiite: Ca Fe 3 Al 6 (Si 5 Al O 18)(BO 3) 3(OH)3 OH
  • Bosiite: Na Fe 3 (Al 4 Mg 2)Si 6 O 18 (BO 3) 3(OH) 3 O
  • Chromium-dravite: Na Mg 3 Cr 6 Si 6 O 18 (BO 3) 3(OH)3 OH
  • Chromo-alumino povondraite: Na Cr 3 (Al 4 Mg 2) Si 6 O 18 (BO 3) 3(OH) 3 O
  • Darrellhenryite: Na Li Al 2 Al 6 Si 6 O 18 (BO 3) 3(OH) 3 O
  • Dravite: Na Mg 3 Al 6 Si 6 O 18 (BO 3) 3(OH) 3 O
  • HElbaite: Na 2(Li 3, Al 3)Al 12 Si 12 O 36(BO 3) 6(OH) 6(OH) 2
  • Feruvite: Ca Fe 3 (Mg Al 5) Si 6 O 18 (BO 3)3 (OH) 3 OH
  • Fluor-buergerite: Na Fe 3 Al 6 Si 6 O 18(BO 3) 3 O 3 F
  • Fluor-dravite: Na Mg 3 Al 6 Si 6 O 18 (BO 3) 3(OH) 3 F
  • Fluor-elbaite: Na 2 (Li 3, Al 3) Al 12 Si 12 O 36 (BO 3) 6 (OH) 6 F 2
  • Fluor-liddicoatite: Ca Li 2 Al Al 6 Si 6 O 18 (BO 3) 3(OH) 3 F
  • Fluor-schorl: Na Fe 3 Al 6 Si 6 O 18(BO 3) 3(OH) 3 F
  • Foitite: [](Fe 2 Al)Al 6 Si 6 O 18(BO 3)3(OH)3 OH
  • Oxy-chromium-dravite: Na 3 Cr 3(Mg 2 Cr 4) Si 6 O 18(BO 3) 3(OH)3 O

Enhancements

Tourmaline gemstones can easily be improved thanks to the many enhancements they can receive. These enhancements can change a stone’s look and color to make it more attractive, and therefore valuable.

  • Heating: This treatment lightens blue and green gems. It is common, stable and undetectable. Black tourmaline are almost impossible to change in color. While pink tourmaline are usually heated from orangish colors to bright pink
  • Irradiation: Produces red, deep pink, yellow and orange colors. May fade under heating or exposure to bright light.
  • Acid Treatment: Bleaches dark inclusions and is primarily used on cat’s eyes. It is stable and undetectable.
  • Filler: These can be both plastic or epoxy and are used to seal hollow tubes, preventing dirt from entering. Detectable with hot point test and magnification.
  • Dyes & coatings: are rarely used as they are unstable.