Spinel

  

Abundant, attractive, affordable and colourful spinels are available in red, pink and blue colour and can occasionally exhibit asterism and chatoyancy. Spinel is a gemstone found in great abundance in Sri Lanka and until the rise of modern gemology in the 19th and 20th Century spinels were often mistakenly identified as Corundums, as they were mostly found in the same mine. Subsequent research into the mineral composition of these two gem families led to their separation and many gem enthusiasts finding that their beloved rubies and sapphires are in fact spinels.

Natural spinel, however, has always been a rare and beautiful gem. Sri Lanka is the second largest supplier of spinel to the global gem and jewellery market with colours ranging from ruby red, pink, orange, shades of reddish-brown, purple, blue, bluish-green, mauve, greenish-black, black to colourless. The occurrence of natural blue spinel coloured by cobalt has been found in Sri Lanka. Cobalt spinel has been found around Ratnapura, Okkampitiya and Embilipitiya. Apart from the common varieties of spinel are also varieties identified as Ceylonite, Gahnite and Ghanospinel.

• Varieties: Star material is very rare.
• Sources: Sri Lanka, Burma, Minor-Anatolia, Afghanistan, Brazil, Thailand, Australia. Toughness Good
• Toughness: Spinel ranks 8 on the Mohs hardness scale. Spinel ranks 8 on the Mohs scale and has good toughness, making it a durable gem for jewelry.
• Precautions: High heat can cause some spinel colors to fade, but spinel is stable when exposed to light and chemicals.
• Treatments: It's always safe to clean spinel with warm soapy water. Some spinel might be subjected to color-altering heat treatment. The treatment is stable under normal wearing conditions. As with any transparent gemstone, spinel might be fracture-filled to improve its apparent clarity.
• History: Two of the stones among the Crown Jewels of England are spinels, although they were once thought to be rubies. They are the Black Prince’s Ruby and the Timur Ruby. The 361 carat Timur Ruby is the world’s most famous spinel. Spinel was recognized as a separate species as early as 1587 in Burma.
• Cuts & Uses: Usually faceted.