In decades and centuries past, two strikingly different reasons have prevented gem spinels from reaching the general public. Many possessed a nasty secondary gray tint to them or, in the case of red spinels, they might be so strikingly spectacular that they passed as exceedingly fine and valuable rubies. Many of the nicest and greatest “rubies” found in royal crowns are in fact red spinels. Thus it is that the “Black Prince’s ruby” and the “Timur ruby”, both of which are in the possession of the British royal family, have turned out to be spinels.
Tanzania is now becoming very famous for its spinels. Spinels from southern Tanzania (Tunduru) are of various colors (purple, blue, etc) while those from central Tanzania (Mahenge, Morogoro), splendid, are usually pink to red.