The Spinel’s beauty is entirely natural, they seldom have to undergo any treatment to achieve their maximum potential. Spinels are singly refractive stones, which means that the light entering the stone, travels in one direction only and does not split into two rays, thus resulting in a stone with enormous brilliance and transparency.
According to the Gemological Institute of America (GIA), the crystals are so perfect, that in Burma they are called nat thwe meaning polished by the spirits. However, until recently Spinels were certainly an underestimated gem. Red and pink Spinels were often mistaken for Rubies or Rubellites (red Tourmalines).
Only in 1783, mineralogist Jean Baptiste Louis Rome de Lisle identified Spinel as a different mineral to that of the Ruby. Therefore, many of the famous Rubies, such as the 14th century Black Prince’s Ruby in the British Imperial Crown, are actually red Spinels.
Spinels are found in a striking array of colors, but the most commercially important are red and pink. The intense reds and pinks are caused by traces of chromium. The higher the chromium content, the stronger the red hue. Whereas the orange and purple stones owe their color to a mixture of iron and chromium. Spinels are found in Burma, Vietnam and Tanzania.