History and General information of Tourmaline Gemstone

The beautiful tourmaline gemstone owes its name to the Sinhalese word Toramalli, which means colorful. A parcel of colorful tourmaline gemstones was sent to Amsterdam from Sri Lanka by mistake and thereafter the Sinhalese name stayed on.

From the 1500s till about sometime in early 1800, dark green tourmaline gemstone was thought to be emerald and was used widely. It was only in 1801 that the gem was tested and was categorized under a separate gemstone group called tourmaline. The famous gemologist George F Kunz popularized the gem later and also introduced it to Tiffany and Co.

Tourmalines have been extensively used in jewelry for centuries. Tourmaline jewelry like tourmaline pendant, tourmaline earrings, tourmaline rings and tourmaline bracelets have been made and purchased over the years. Tourmaline birhtstone is very lucky for people born in the month of October.

A study of the old gems reveals that tourmaline gemstones has been used in jewelry for over 2000 years. A carving of Indian origin (now housed in the Ashmolean Museum in England), of Alexander the Great on purple yellow tourmaline is said to belong to the 2nd or 3rd century B.C.

Composition of Tourmalines

The answer to what is tourmaline, is that it is a complex boro-silicate of alkalis and metals [(NaCa) (Li Mg FeAl)9 B3 Si6 (O,OH)31]. Its specific gravity ranges from 3.03 to 3.15 and its refractive index ranges between 1.622 and 1.641. The gem’s hardness on Mohs scale falls between 7 and 7.5.

Recent research has revealed that the natural tourmaline gemstone has pyroelectic and piezoelectric properties, which help in amplifying psychic energy and neutralizing negative energy. As a result, tourmalines are widely used in crystal therapy. The gemstone is also put to industrial use.

Varieties

There are almost ten varieties of tourmalines but only a few of them are used in jewelry. Most of the names listed below are trade names. Varieties of tourmaline are often popularly referred to by their natural color e.g. green tourmaline, pink tourmaline, purple tourmaline, blue tourmaline, blue-green tourmaline, yellow tourmaline, pink tourmaline and so on.

1. Rubelite gem - pink to red color.- pink tourmaline or red tourmaline. 

2. Indicolite tourmaline - deep rich pinky blue color- Purple tourmaline.

3. Siberite - lilac-violet-blue color- Blue Tourmaline.

4. Verdite – natural green color. A natural green tourmaline necklace has been a favorite with many for a long time- Green Tourmaline.

5. Watermelon tourmaline - Center color pink with green color on the side, this bi-color natural tourmaline gem looks like a tourmaline slice of water melon and has multiple tones in it.

6. Schorl- black color. Black tourmaline jewelry that uses black tourmaline beads and faceted stones has been used since time memorial. They are not very popular in the recent times and is mostly collected as a collectors item- Black Tourmaline.

7. Dravite - yellow-brown to dark brown color. Brown or Yellow Tourmaline.

8. Liddicoatite - brown, blue or pink/green parti color tourmaline.

9. Achroite - colorless. White or color less Tourmaline.

10. Tourmaline cat's eye

11. Paraiba Tourmaline - green to blue or violet color. This is the trade name for the rare quality gem and the very expensive vibrant green to violet or blue tourmaline gem that is found in Brazil. The name comes from the place of its origin - Paraiba. It's extraordinary color and rarity has made it the most expensive gem in the tourmaline group. This gem owes its unique color to trace elements manganese and copper. Most of these copper bearing tourmaline gems are custom-cut and used in custom-made exclusive jewelry due to its high value.

Physical Properties

Tourmaline Color

Tourmalines are found in every color that one can think of - pink, deep pink peach, red, green, dark green, peach,  purple red,  blue, blue green, yellow, black, bi colored, colorless and even in multi-colors (for e.g. a single long crystal of tourmaline is sometimes half pink and half green called parti-colored tourmaline).

With such a variety of colors it goes without saying that trace elements that cause the color are also varied. They various minerals or trace elements that can be found in tourmalines are iron, titanium, chromium, vanadium to manganese and sometimes even copper. 

Cut

Since natural tourmalines are found in elongated crystal forms, many a gem is cut into long rectangular shapes. Besides rectangular shapes, the gem is also cut into regular round, square shape, octagon cut, oval cut or into dome shaped cabochons. The gemstone is widely used in jewelry and also for exclusive carved pieces for which the tourmalines are cut and faceted in a customized manner.

Carat

Usually tourmaline crystals are found in elongated forms that are often in bi-color. Large tourmaline roughs above 200 cts have been found in nature.

Clarity

Clear and clean gemstones with no inclusions or totally clean natural tourmaline crystals are not that tough to find and demand good prices too.  Natural tourmalines that are completely flawless can also be found. These tourmalines do not have any eye visible inclusions. Faint natural inclusions can reduce the price based on how much magnification is required to see the inclusion easily.

Price and Buying of Tourmaline Gemstone

There are so many varieties of tourmalines that a general price range is very hard to define. The price for an excellent and rare quality 3 ct natural rubellite-pink tourmaline can be for US$30 per carat whereas a paraiba tourmaline gemsotne of around 25 carats can fetch around US$4000. In a wider perspective, small size tourmaline gemstones can come in the range of $1 per carat to $100 per carat depending upon the cut, clarity grade, and color and carat size.

Green, blue, pink and red tourmaline gemstones are commonly used in jewelry. The paraiba tourmaline and the parti colored or watermelon tourmaline are mostly used in custom made designer jewelry due to its uncommon coloring.

Markets and Producers

Brazil is the main source of fine quality tourmalines. Besides Brazil, tourmalines are mined in India, Russia, Sri Lanka, Burma, Brazil, California and other countries in Africa like Tanzania, Namibia, Zimbabwe, Kenya and Madagascar.

Treatments

The most common treatments carried out on these gems are heat and irradiation. These treatments are mostly done not to change the color of the gem, but only to enhance it. Unheated and untreated tourmalines are also available in the market.

Simulants

Just like the varied colors of gems in the tourmaline group, numerous simulants of tourmaline are seen in the market. These are zircon, apatite, paste, all beryls, garnet, ruby, all sapphires, quartz, scapolite, and spinel.

Interesting Trivia and other Tourmaline facts

Tourmaline is the official state gem of Maine, USA. Pink tourmaline rings and pink tourmaline pendants are used for its metaphysical properties. It is worn by the people born in the month of October and hence called as the October Birthstone.

Reference

1) Webster
2) Gemmology by Peter G.Read
3) Handbook of Gem Identification -   Richard  T.Liddicoat, jr
4) Gems and Crystals - From the American  Museum of Natural History - Anna S.Sofianides  and George E. Harlow.