Taaffeite is a rare oxide, which is notable for being the only known mineral to contain both beryllium and magnesium within its fundamental composition. Usually, but not always, associated with pinkish, purplish and/or violetish hues, it is one of the world’s rarest gem materials.
The gemstone was named in honor of the Austrian gemologist Richard Taaffe, who in 1945 had purchased a faceted “spinel” from a Dublin jeweler. However, unlike what would be expected for a genuine spinel, the specimen was optically anisotropic and was therefore determined to belong to an entirely new species. As a result, taaffeite was, and remains, the only mineral to have been initially described from faceted samples, rather than while still in its natural form.
First discovered in 1967, musgravite is almost indistinguishable from taaffeite.The two minerals differ very slightly in their composition, with raman spectroscopy usually required to separate them.