Tourmaline Gemstone

With many gemstones on the market, it can be hard to find one that suits your style and which makes you stand out. Thanks to its unique properties, tourmaline is a one of a kind gemstone that can exhibit more than one colour depending on the angle from which you look at it.

What is tourmaline?

Tourmaline is basically a crystalline silicate mineral that is comprised out of a multitude of elements. In tourmaline you can finds potassium, lithium, sodium, magnesium, aluminium, iron and others. According to the professional classifications, tourmaline is seen as a semi-precious stone which can be found in a multitude of colours. The chemical composition can affect the colour of the stone and the presence of iron in particular can positively effect a tourmalines value.

History

This gemstone was discovered for the first time in Sri Lanka and it was sent to Europe during the 15th-16th century. In the 18th century many people called it a Ceylonese magnet because of its magnetic and pyroelectric properties - repelling hot ashes. Thanks to these properties, chemists used it during the 19th century in order to polarize light, amongst many other things.

Tourmaline varieties and colours

Tourmaline can be found in 3 different varieties. You have the Schorl which is most of the time encountered in a brownish black or plain black form, and then you also find the Dravite which is encountered in dark yellow to brownish black. The last variety comes in the form of Elbaites, and these are more different because they come in many colors. The rubellite, verdellite, achroite and indigo are the main Elbaites that are found.

Tourmaline structure

This mineral comes in the form of a six-member ring of cyclosilicates, provided in a trigonal system. It's a long set of crystals that bring a set of curved striated faces.

What makes tourmaline distinct and very different when compared to other minerals is the fact that it has a prism, which has three sides. Because of that, it is a unique mineral as none other can be found which holds such properties.

Magnetism

Many types of tourmaline come with magnetic capabilities, which come mostly from the high iron concentrations that you can find in them. Because of that, tourmaline is used in a variety of mediums in order to detect metal.

Tourmaline treatments

Some tourmalines are treated in order to improve the current colour. In order to do that they need to be altered with a heat treatment. It's important to note that the clarity enhanced tourmalines have a reduced value when compared to the normal, non-treated tourmaline.

Brazil is the world's largest producer of Tourmaline with some of the finest blue examples of the stone being found there. Other locations include Afghanistan, Sri Lanka and many countries in Africa, including Namibia. We visited Namibia for 5 weeks at the start of 2015 in search of some Tourmalines to buy as well investigating ethical mining practises in the country.