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Download hereGENERAL DESCRIPTION
Brazilianite is a hydrated sodium aluminophosphate. This hydrothermal mineral is very rare, being formed in the pegmatites areas that are enriched in phosphates but also in some metamorphized sedimentary deposits.
Its crystals, often centimetric, are of yellow colour with green yellow and transparent. They are prismatic, short, forming aggregates. They are often associated to muscovite and other phosphates (apatite, montebrasite...). The faces of their prisms are striated or lengthened.
The deposits are very few. Among most remarkable: Conselheiro Pena and other mines of Minas-Gerais (Brazil); the Palermo mine and the Charles Davis mines in New Hampshire (USA).
No French deposits are yet known despite it has been found in Austria, Germany, in Czechlands and Spain. Although fragile, brazilianite is used in jewellery.
The type of this species is preserved at the National Museum of Natural History of Washington (USA)
HISTORY : Named in honour of the country of its type-locality : Brazil
Species first described in 1945 by Pough and Henderson, American mineralogists
Type-locality: Conselheiro Pena, Minas Gerais, Brasil
CHEMICAL FORMULA : Na Al3 (PO4)2 (OH)4
CRYSTAL SYSTEM : Monoclinic
COLOR : Jaune
DIAPHANIETY : Transparent
LUSTER : Vitreous
STREAK : White
MORPHOLOGIE : Isolated crystals or well-developped crystal aggregates, sometimes as spherules or rounded aggregates
HARDNESS : 5,5
CHEMICAL CLASS: 2,98
DENSITY : VII - Phosphates, arsenates and vanadates
GROUP : Brazilianite - viitaniemite series
STRUNZ CLASS BEFORE 2001 : 7/B.12
STRUNZ CLASS AFTER 2001 : 8.BK.05
