A gemstone that fascinates all that behold her.
An electrifying green coloured Tourmaline whose vivid saturation makes the gem a favourite with collectors and connoisseurs alike.
Similar to Emerald and Chrome Diopside (also known as Russian Diopside) Chrome Tourmaline receives its colour from the presence of chromium (and to a small extent traces of vanadium, similar to some Emeralds).
Most Green Tourmalines you will see are from the elbaite family within the Tourmaline group. Although Green Tourmaline per se is not as rare as other colours of Tourmaline such as red (known as Rubellite) and blue (called Indicolite), Chrome Tourmaline from the dravite part of the Tourmaline family is incredibly rare.
Just like valuing Emeralds, the more pure the green hue is, the more valuable the gem becomes, but also like Emeralds there is normally either a slight hue of blue or yellow witnessed. This of course is not surprising when you understand that Tourmaline is the most dichroic of all gemstones. As with Blue Tourmaline, Chrome Tourmaline is a real outdoor kind of gemstone. Indoors its colour tends to close up and the gem loses a little of its diaphaneity, but once in incandescent light its vivid colour explodes and its transparency opens up.
In terms of carat weight, most pieces are less than half a carat in weight and on the odd occasion a piece is over one carat, the demand in the market, especially from collectors is so high, that the gem can demand a premium often similar to that of Indicolite and fine quality Rubellite.
The gem’s vivid colour is provided by the presence of the element chromium, however in pieces where there is a slight greyish mask diminishing the impressive level of the gems colour saturation, it is normally caused by either too high a concentration of either chromium or vanadium.
So what is the difference between Is your gem Green Tourmaline or Chrome Tourmaline and how can you tell the difference? Well, the answer is surprisingly simple. Regular Green Tourmaline receives its colour from the presence of iron and Chrome Tourmaline, as already mentioned, receives its vivid colour from traces of chromium. If you own a green Tourmaline and want to discover if its colour is attributable to chrome or iron, then simply purchase a Chelsea Filter (see separate feature). As you view your gem through it, if it contains chromium you will see flashes of red, if your gem is coloured by iron then your gem’s colour will remain unchanged.
Chrome Tourmaline has so far only been discovered in Tanzania.