Taaffeite (/ˈtɑːfaɪt/; BeMgAl4O8) is a mineral, named after its discoverer Richard Taaffe (1898–1967) who found the first sample, a cut and polished gem, in October 1945 in a jeweler's shop in Dublin, Ireland.

Upon noticing inconsistencies between the taaffeite and spinels, Taaffe sent some examples to B. W. Anderson of the Laboratory of the London Chamber of Commerce for identification on 1 November 1945.

When Anderson replied on 5 November 1945, he told Taaffe that they were unsure of whether it was a spinel or something new; he also offered to write it up in Gemologist.

[9] Unlike spinel, taaffeite displays the property of double refraction that allows distinction between these two minerals.

This extremely rare mineral is increasingly found in alluvial deposits in Sri Lanka[11] and southern Tanzania,[2] as well as lower grade taaffeite in limestone sediments in China.