Spinel usually occurs in various shades of red, pink, orange, lavender, blue, purple, brown, grey and black. Some spinels are among the most famous gemstones: Among them is the Black Prince’s Ruby and the ‘Timur ruby’ in the British Crown Jewels, and the ‘cote de Bretagne’ formerly from the French Crown jewels. The ‘Samarian Spinel’ is the largest known spinel in the world, weighing 500 carats (100 g). The transparent red spinels were formerly called spinel-rubies or balas-rubies. In the past, before the arrival of modern science, spinels and rubies were equally known as ‘rubies’. After the 18th century the word ‘ruby’ was only used for the red gem variety of the mineral corundum and the word ‘spinel’ became used. Spinel is a durable gemstone that is perfect for all jewelry uses.