Tourmaline, October’s Birthstone
Tourmaline is a semi-precious gem that can be found in very large crystals, some weighing many kilograms. Because the gem is found in a wide range of colours, it is suitable for almost anybody’s taste. Some tourmalines even show more than one colour in a single gemstone. Bi or tri-coloured gems are found in many combinations, but the ones with a well-defined colour boundary are the most highly prized.
Tourmaline is found in many places around the world including Brazil, Afghanistan, the USA, and East Africa.
The word tourmaline is derived from the Sinhalese word ‘turmali’ the name given to all coloured crystals in Sri Lanka.
Because of their many colours and the multiple sources of the stones, they have, for many centuries been confused for other gems such as rubies and emeralds.
As a birthstone gift, they are fashionable because they look outstanding when cut to give sparkling facets, there are many colours to suit all tastes and the price, given that they are classified as semi-precious gems rather than precious gems, makes their purchase more accessible than some other fine gemstones.
The History of the Tourmaline
Tourmaline came to Europe through merchants of the Dutch East India company in the 17th century. At about the same time, the same crystal was found in Brazil by Spanish conquistadores, but they thought they had found emeralds. Of course, tourmaline had been found in these parts of the world well before the arrival of Western merchants and soldiers. The Chinese have used tourmaline for carved and engraved pieces for many hundreds of years. A relatively common item handed down over the years are pink tourmaline snuff bottles that are a testimony to the durability of this hard, crystalline stone.
The ancient gem traders had a problem – they were unable to distinguish between the coloured gems that were tourmaline and other coloured gemstones and so they were routinely misidentified. Today there are artefacts that we now understand to be tourmaline but that were initially thought to be made with rubies; the Russian imperial crown jewels are one such example.
The Meanings Associated With Tourmaline
As a birthstone, tourmaline is held to increase the wearer’s love of humanity, making the wearer happier, more optimistic, compassionate and yet grounded in the real world.
Tourmaline has had a special meaning for many cultures. In Europe, by the 18th century, people believed that wearing the gem would help actors, artists and other creative people. A Dutch scientist used a tourmaline to help feverish children to sleep. In Africa, black tourmaline was thought to help bring people into a trance state. Romans used tourmaline to bring on a relaxed sleep, calming both mind and body.
Ancient Egyptians had a legend that tourmaline came from the centre of the earth, passed over a rainbow, absorbing all the colours to make the many colours of tourmaline.
Today some alternative therapists claim that black tourmaline, sometimes called schorl, can provide pain relief to torn or strained muscles, reduce arthritic pain and decrease scar tissue. They think that schorl can help balance the right and left sides of the brain, reduce paranoia and improve hand to eye coordination.
Tourmaline’s Geology and chemistry
Tourmaline is formed in igneous rocks called pegmatites. Pegmatites are crystalline rocks with individual crystals ranging in size from a couple of centimetres to 10 meters or more. Pegmatites form in voids deep under the surface of the earth. The voids were filled with molten material rich in minerals when the liquid magma liquid begins to cool Tourmaline, and other crystalline stones are formed.
Tourmaline In jewellery
The most popular colours for tourmaline are green and pink. The gemstones can be cut with facets to enhance their colour and brilliance.
Red and pink tourmaline:
This is the classic tourmaline colour and the colour most people recognise as being tourmaline. This is the most commonly found colour and has the lowest cost.
Paraiba tourmaline:
Paraibas are highly prized with a neon greenish blue colour derived from copper. The richness of the colour has an effect on the price.
Green Tourmaline:
Mint green tourmaline isthought by many to be the best. Green tourmaline can be found in a wide range of sizes. Green stones are not treated with heat or radiation to modify the colour or quality.
Chrome tourmaline:
Chrome tourmaline has a very strong green colour which comes from the chromium in the gem. Usually, chrome-coloured tourmalines come in smaller sizes.
Canary tourmaline:
These stones have a particularly vivid yellow colour. Canaries are generally smaller stones and are very rare.
Blue tourmaline:
Of all the typesof tourmaline, only the blue variety called indicolite is a precious stone, all other kinds are semi-precious. Indicolite has a very strong blue colour. Where the original stone has a greenish cast, it is often removed with special treatments. Indicolite usually has inclusions, a skilled cutter can minimise these.
Watermelon tourmaline:
This is an unusual stone with a green layer separated from red by a layer of clear stone. This gives the appearance of a watermelon, hence the name. Cutting the gems to maximise the effect is a skilled craft. The best examples of watermelon tourmaline have a 50/50 blend of green and red.
Tourmalines are often manipulated to alter their colour. These treatments change the tone and depth of the colour. Unfortunately, over time these changes fade due to exposure to heat and light.
There are two main ways that tourmalines are treated: heat and oil/resin. A heat treatment can give a better colour for the stone but does not change the hardness or durability. Oil or resins can be injected into a gem; however, this can make the stone more prone to damage, they are often much cheaper than unaltered stones.
Tourmaline is not as hard as diamond with a Mohs scale rating of 7-7.5 as compared to a diamond at 10. This lack of hardness makes the stone much less durable and so care must be taken with tourmaline jewellery that is intended to be worn every day. Tourmaline has a long history with many twists and turns. Enjoy the range of colours in any jewellery but take care of it because it is more fragile than many other gemstones.