General Information

Spinel is a gemstone that occurs in an amazing array of colours, from intense stoplight red to all shades of pink, purple blue and violet. Greenish stones are occasionally found but are quite rare. Spinel has historically been an extraordinarily popular gemstone with several incredible specimens being found in the Crown Jewels of England, Iran and India, and in private collections around the world. Spinel is pure in colour and very durable. With a hardness of 8, it is suitable for frequently worn jewellery.

Pure spinel is colourless, with the wide range of colours caused by trace amounts of other materials. Spinel is a singly refracting stone, and therefore shows a pure hue with no secondary colours. For thousands of years, spinel was mistaken for ruby, and the red material will often be as good as or even superior to ruby. Indeed, ruby and red spinel are found in the same deposits in Myanmar, so confusion is understandable.


Spinel quality is dependent on the beauty of the stones colour, as spinel tends to be relatively inclusion free. Look for a bright stone with an appealing colour, in an attractive size and shape; these factors are purely personal.


Spinel is a gemstone that is generally free from treatment, though some filled material is available on the market.


The folklore of spinel is closely intertwined with that of ruby, as the two materials have been confused for thousands of years, due to their similar appearance and the fact they are often mined together. Most lore will refer to spinel as ‘Balas Ruby’. The most famous spinel is known as the Black Princes Ruby, an approximately 170ct polished, uncut spinel, which can be found set in the Imperial State Crown in the British Crown Jewels. Any characteristics related to spinel tend to be colour related, for example red spinel for physical vitality and violet spinel for spiritual development.


One of the great advantages of spinel is its durability. It can be safely cleaned with any detergent and is suitable for ultrasonic cleaning. Spinel with prominent inclusions are more likely to break if subjected to a sharp or heavy knock, however all jewellery should be treated with sensible care. Also consider that a setting needs occasional maintenance to avoid the possibility of it loosing its grasp on your precious treasure.

Scientific Information

Chemical Composition     MgAl2O4 (Magnesium Aluminate)

Crystal System                Cubic

Refractive Index              1.719

Specific Gravity                3.60 - 4.10

Hardness                         8

Cleavage                         Indistinct

Fracture                           Conchoidal

Lustre                              Vitreous