Tourmaline, along with opal, is the official birthstone for October. It is also the gem that celebrates the eighth anniversary.
Owing to its wide range of colour availability, this gemstone is considered to be one of today’s most versatile gemstones.
Its name is thought to be derived from the Sinhalese word, “turamali”, which means “stone with various colours” in reference to its extreme versatility.
It’s a term Dutch merchants applied to the multicolored, water-worn pebbles that miners found in the gem gravels of Ceylon (now Sri Lanka).
People have used tourmaline as a gem for centuries, but until the development of modern mineralogy, they identified it as some other stone (ruby, sapphire, emerald, and so forth) based on its coloring.
In 1875, George Kunz, an American mineral collector, introduced the green variety from the Mount Mica mine in Maine, USA to Tiffany & Co., which sparked an interest in tourmaline and led to its popularity on the mainstream jewellery market.
Brazilian discoveries in the 1980s and 1990s heightened its appeal by bringing intense new hues to the marketplace.
Tourmalines come in a wide variety of colors. In fact, it has one of the widest color ranges of any gem species, occurring in various shades of virtually every hue.
It’s generally agreed that traces of iron, and possibly titanium, induce green and blue colors. Manganese produces reds and pinks, and possibly yellows.
Some pink and yellow varieties might owe their hues to color centers caused by radiation, which can be natural or laboratory-induced.
Many tourmaline color varieties have inspired their own trade names:
Rubellite is a name for pink, red, purplish red, orangy red, or brownish red tourmaline, although some in the trade argue that the term shouldn’t apply to pink tourmaline.
Indicolite is dark violetish blue, blue, or greenish blue tourmaline.
Paraíba is an intense violetish blue, greenish blue, or blue variety from the state of Paraíba, Brazil.
Chrome tourmaline is intense green. In spite of its name, it’s colored mostly by vanadium, the same element that colors many Brazilian and African emeralds.
Parti-colored tourmaline displays more than one color. One of the most common combinations is green and pink, but many others are possible.
Watermelon tourmaline is pink in the center and green around the outside. Crystals of this material are typically cut in slices to display this special arrangement.
Some stones also show a cat’s-eye effect called chatoyancy. Cat’s-eye varieties are most often green, blue, or pink, with an eye that’s softer and more diffused than the eye in fine cat’s-eye chrysoberyl.
Tourmaline is found in pegmatites and alluvial deposits all over the world. It is also the national gemstone for the United States, where it has been mined for centuries.
Today, the most significant deposits come from Minas Gerais and Bahia, Brazil. Other notable sources include Afghanistan, Australia, and Burma (Myanmar).
Most stones are completely untreated. However, some stones may be heated to improve colour and clarity.
Yellow, pink and red varieties of may be irradiated to enhance colour, although irradiation is nearly impossible to detect and does not normally affect value.
Heavily included rubellite and Paraiba stones may be clarity enhanced.
Tourmaline gemstones are quite tough and durable which makes them ideal for jewelry use. However, due to their pyro-piezoelectric properties, tourmaline gemstones do need to be wiped down frequently as they tend to attract more dust and particles than most other gemstones.
To clean your tourmaline gems, simply use warm soapy water and a soft cloth. Be sure to rinse well to remove soapy residue. As with most gemstones, ultrasonic cleaners and steamers are not recommended.
Store these gemstones away from other gemstones to avoid scratches. It is best to wrap gemstones in soft cloth or place them inside a fabric-lined jewellery box.
We hope this article has given you a bit more of a background on tourmaline, but should you have any additional questions about this or any other jewellery related topics, you can always: “Ask the Jeweller”
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