Tourmaline offers a beautiful rainbow of colours, with no other gemstone having quite the same range of hues, or even stones that have more than colour!
The gem was recognised as a distinct mineral species in the 1800s, often being confused with other gems previously. The name tourmaline originated in Sri Lanka, deriving from the Sinhalese meaning ‘mixed gems’ and referring to the multi-coloured assortment of crystals found in the gem gravels of that country.
Typically sold using a colour prefix such as pink or green tourmaline, some varieties also have their own names, such as rubellite for red or indicolite for blue.
A rare variety with a vivid blue to green colour is Paraiba tourmaline, first discovered in the state of that name in Brazil although the name is often now applied to similar gems from Mozambique and Nigeria. The presence of traces of copper gives a stunning ‘pop’ to their colour.
It is not uncommon for a single tourmaline crystal to display more than one colour due to alterations in the chemical environment during growth. The crystals form as long prisms with a rounded triangular cross-section and those displaying more than one hue may vary along the length (so one end of the crystal is one colour and the other end a different colour) or have concentric zones of different colours when viewed in cross-section. Because of the range seen in tourmaline it is possible to see a variety of combinations, but the most common is green and pink. A variety called watermelon tourmaline is often cut into slices to display a bright pink centre framed by an outer zone of green.
Tourmaline also exhibits strong pleochroism, a property that is connected to the way light interacts with a gemstone and means that it can appear different colours when viewed from different directions, in tourmaline’s case often darker and lighter shades of the same colour; darker when viewed along the crystal and lighter when viewed from the side.
It is quite common to encounter carved tourmalines in both jewellery and decorative objects, since it can form in large sizes and such a range of colours. The gem is rather prone to inclusions, and using it in this way, or for beads, cabochons, and rose cut gems, really shows off the beautiful colour in material that would not be especially attractive as a faceted gem. The inclusions can then add texture to the gem’s appearance and give each stone a unique look.
If you would like to learn more about tourmaline or view our tourmaline jewellery please visit our showroom or you can also view some of our tourmaline jewellery on our website.