Due to its Mohs hardness of 8, the spinel is one of the hardest coloured gemstones and is therefore ideal for processing as a piece of jewellery. The spinel occurs in different colours, with the red and cobalt blue spinel being the most valuable varieties.

The most important deposits of the spinel are located in Myanmar, Tanzania, Vietnam and Tajikistan. It is interesting that prominent gemstones from the British crown jewels were mistakenly thought to be rubies for a long time – in reality they are spinels.