s
Russian Gemstones Encyclopedia

Vladimir Bukanov. Russian Gemstones Encyclopedia

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

TAAFFEITE


TAAFFEITE (Taaffeit—Taafféite—“аффеит) (Anderson, B.W. & Claringbull, G.F. 1951), after Edward Charles Richard Taaffe (b. 1898), a gemologist from Dublin, Ireland. Oxide – Mg3BeAl8O16, the group of spinel, hexagonal system. Hardness 8. Density 3.6. Glass luster. Color: pale green, pink, and red, lilac to purple, sometimes colorless. Red-violet color depends on the admixture of chromium (Cr3+). Transparent to translucent. Taaffeite is a rare mineral, which is represented with small isometric crystals and coarse-grained aggregates. Its transparent crystals were previously taken for spinel. It is formed under contact metasomatism of carbonate rocks. The first finding of taaffeite, 0.55 ct. in mass, among faceted spinel, was made by the Irish gemologist E. Taaffe in 1945. The second stone, in 0.86 ct., was found in the Geol. Museum, London; the third one, in 0.84 ct., – in the collection of GIA. On placers of Sri Lanka, at the Eheliyagoda, near Ratnapura, they found 30 samples of gravel crystals, the biggest of which, from the Elahara deposit, was 71.11 ct. in mass. On Sri Lanka, they found also gem-quality taprobanite, which later was classified as an intermediate variety between spinel and taaffeite. Beside Sri Lanka, lilac taaffeite was discovered on placers of Myanmar (Burma). There, from transparent fragments they make faceted stones, the biggest of which was a bit more than 3 ct. In China, large sapphire-blue crystals of taaffeite were discovered at the Syanhualin deposit, in the Hunan Prov. In South Australia, violet-blue taaffeite was found in the Masgrave Mts., near Mt. Painter. It was discovered even in Antarctic, in Casey Bay, Enderby Land Is. But the most part of these findings are still of no practical interest. In Russia, accessory taaffeite was found in rare-metal micaceous rock of the Middle Urals, Aduiskiy massif; as well as in Karelia, at the Pitkaranta deposit, Priladozhia.

Synonyms. Bemagalite | Berinel | Taprobanite, from Gk. name of Taprobane – Sri Lanka | Tarfit.

Search