Taaffeite (BeMgAl₄O₈) is a mineral, named after its discoverer Richard Taaffe (1898-1967) who found the first cut and polished gem in November 1945. As such, it is the only gemstone to have been initially identified from a faceted stone. Most pieces of the gem, prior to Taaffe, had been misidentified as spinel. For many years afterwards, it was known only in a few samples, and is still one of the rarest gemstone minerals in the world.