Spinel

The mineral spinel produces a lovely suite of gemstones with various hues and tones. Next to ruby, it is probably the most sought after of all red gems. In some cases, the colour of spinel is much brighter and vivid than that of ruby. Its high hardness, 8 on the Moh’s scale of hardness, adds to it being durable to wear even in rings.


What are the colours of spinels?

Spinel can be found in various colours varying from the lightest pink to bright traffic signal red. A beautiful flame-orange colour can also be found. Other important colour is blue - ranging from a magnificent cobalt-blue to a more subdued bluish green. Violet and purple colours are also common. Pure colorless is almost non-existent and can always be found along with traces of pink. This becomes clear when one compares it side by side with a colorless synthetic spinel. Also, a rare colour to obtain is green. In most cases, due to high iron content the green colour has such a dark tone that it appears almost black.


What spinels are considered expensive?

In case of spinels, the most expensive colour is red. Next to red diamond and ruby, spinels are the most expensive stones with prices up to $1000 per carat for sizes above 3 carats. In fact, many of the large gems considered as rubies throughout history have now been recognized as spinels. An example is the Black Prince’s Ruby which is set in the Imperial State Crown, which is actually a spinel. So is the Timur Ruby possessed by the British royal family which also is a spinel.  Also equally expensive to the red spinels are the blue spinels called Starlite. Relatively inexpensive are the black spinels called Ceylonite or Pleonaste. Green spinels of a light tone are considered expensive. Other fancy colored spinels are inexpensive and the price depends upon the saturation and vividness of the colours. One of the most expensive spinel is the zinc spinel called Gahnite.


How to identify a spinel?

A Spinel is a Magnesium Aluminium Oxide. It is isotropic in nature meaning that it has only one refractive index (most stones are anisotropic i.e. they have two refractive indices). Due to this property is also does not show pleochroism (a property by which the colour of the gemstone appears different when viewed in different directions). Also, red spinels turn red when seen under long wave U.V. light due to their chromium content.

Rough Burmese Spinels:

View our inventory of Spinels