One of the most newly discovered minerals. It was identified by the
American minerologists
Pough and
Henderson in 1945 and named after the country where it was discovered. It occurs in the form of perfect crystals grouped in druses, in pegmatites, and is often of precious-stone quality. The only noted deposit of brazilianite is in the surroundings of
Conselheiro,
Pena, in the state of
Minas Gerais in
Brazil. During the past few years this deposit has yielded a great quantity of beautiful raw material, which has included crystals of surprisingly large dimensions and perfectly bounded crystal faces.
Some of these are found on leaves of muscovite with their strong silvery glitter, ingrown in their parent rock. Such specimins of course are not ground, but find their way into museums and private collections. The most exquisite crystals, dark greenish-yellow to olive-green, sometimes measure up to 12cm in length and 8cm in width. Crystals of similar shape and dimensions have discovered in another deposit in Minas Gerais, near Mantena, but they lack the perfection of the crystal bounding. Brazilianites have also been discovered in many large collections; they were from the Palermo mine and the Charles Davis mine near North Grafton (Grafton County), New Hampshire, USA. It is a much sought after precious stone, usually ground into facet cuts, and it is a very popular item with collectors.