Tourmalines are fascinating gemstones. They are known for their incredible array and saturation of colours and have been mistaken for other gemstones for centuries. The name itself is a testimony to this confusion. It derives from the Sinhalese language meaning ‘mixed gem’ and only started to be used in the XIX centuries, far after the first tourmaline was discovered, used in jewellery, or confused for emeralds by the Spanish conquistadors.
How Tourmalines Are Formed
Tourmalines form as igneous rocks, from magma deposits cooling down and solidifying in the Earth’s crust. The type of rocks formed through this process are called pegmatites. A variety of factors including the slow decrease in temperature, cause tourmalines to often grow in large crystals with the typical triangular base prismatic shape and vertical striations on the crystal faces.
The chemical environment of the magma and gasses, rich in trace elements, is the primary cause of colour in the stone. Elements such as iron (Fe), manganese (Mn), chromium (Cr), vanadium (V), and copper (Cu) impart green, blue, brown, yellow, red, pink, and purple hues in tourmalines. Some colours are more desirable and have been renamed by the trade due to their popularity. For instance, indicolite is the greenish-blue variety of tourmalines, rubellite is the pinkish-red, Paraiba is the neon blue, watermelon is the variety with a pink/red core, a colourless band, and a green rim. The presence of multiple colours in these gemstones - often two, thereof the name bi-colour – is due to the slight change in chemical elements during the growth of the crystals over millions of years. As a result, this characteristic attracts interest from jewellers and designers for its peculiarity.
Mining Tourmalines
Mining locations for this gemstone can be found all over the world, some of the most well-known mines are in South America, Brazil for instance is the home of the Paraiba tourmalines, which were originally only mined in the Paraiba state. Nowadays Africa produces some of the best examples on the market, including Paraiba, from countries such as Nigeria, Mozambique and Madagascar. Historically, the United States had a strong export market of tourmalines, and although the production is not as high at the moment, they are still mined well-formed crystals. Additionally, Afghanistan and Sri Lanka have also been known for their production of tourmalines since the 1800s.
Tourmalines at Auction
Gemstones | Tuesday 16th July 2024
Viewing times (ID required):
Birmingham
Monday 15th July 10:00 – 16:00
Virtual viewings are available by request. Virtual viewings are the ultimate personal shopping experience. Using Zoom, you can ask us whatever you need to know to buy with confidence. Find out more here.
Newsletter Signup
Newsletter
