Colour-change Chrome Tourmaline, faceted, Mozambique. 1.07 carats. ** SOLD **

Product Code: TRCC20
Units in Stock: 0
** SOLD **

A faceted, transparent green chrome-bearing Tourmaline with a remarkable colour-change effect.

In daylight it appears a deep green colour, but in incandescent light it reverts to a yellow-red colour (image 2).

The effect is unlike many colour-change gem varieties in that it can often only be seen when light is shone onto the front of the stone, rather than transmitted through it.

This is most probably due to the Usambara effect, a phenomenon best seen in larger rough Tourmaline gems from this source where light must pass a sufficient distance through the stone for the phenomenon to be visible.
In the case of faceted gems, the internal reflection of light add to the path distance and the effect becomes apparent.
The effect can also be seen clearly if a gem is placed on a mirrored surface under incandescent illumination.

A rare and unusual gemmological curiosity from a unique find in Mozambique.

weight:  1.07 carats
shape:  Drop cut
dimensions:   8.63 x 5.90 x 3.93 mm
treatment:  None