It wasn’t until about 150 years ago that the spinel was recognized as a mineral in its own right. Lo and behold: some well-known ‘rubies’ turned out to be spinels, among them the Black Prince’s Ruby in the English Imperial State Crown and the pear-shaped stones in the crown of the Wittelsbachs of Bavaria. Traditionally spinels have long been found in the gemstone-bearing mines in Burma and Sri Lanka but more recently also in the excavations at Tunduru in Tanzania, Ilakaka in Madagascar and Luc Yen in Vietnam.
Spinels occur in various shades of pink, red, blue, green, yellow, grey and violet. The most sought-after ones are the red. The rariry of this 13-carat Vietnamese spinel lies in its remarkable size and pure colour.