Brazilianite - Encyclopedia

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous phosphate
    Crystal system : Monoclinic
    Chemistry : NaAl3(PO4)2(OH)4
    Rarity : Rare

Brazilianite is a mineral typical of granitic pegmatites, associated with muscovite, albite and tourmaline. It owes its name to its country of discovery : Brazil. Brazilianite occurs in short prismatic to isometric crystals, with striated or elongated prism faces, sometimes lanceolate, in flat crystals of octahedral appearance, also in fibroradiated globules. It is sometimes massive and porous. Transparent with a glassy luster, brazilianite is a characteristic greenish yellow, more rarely white or colorless. It is a rare mineral appreciated by collectors, which can be cut into gemstones.

Brazilinaite in the World

Brazilianite is, as its name suggests, a Brazilian mineral : all the exceptional crystals come from Minas Gerais which provided gemmy crystals reaching 20 cm and doubly-terminated prisms of 5 cm (Corrego Frio near Divinodas Laranjeiras), as well as yellow-green stony crystals of 10 to 25 cm, respectively in Galileia and Sao Geraldo, near Conseiheiro Pena. Brazilianite is also known as centimetric colorless fibroradiated globules in pegmatites in the district of North Groton (New Hampshire).

Brazilianite in France

In France, the only deposit to have produced brazilianite is Echassières (Allier), where it has been identified in microcrystals.

Twinning

No twinning known for this mineral species.

Fakes and scams

No fake inventories for this mineral species.


Hardness : 5.5
Density : 2.98
Fracture : Conchoidal
Streak : White

TP : Translucent to transparent
RI : 1.602 to 1.623
Birefringence : 0.020
Optical character : Biaxial +
Pleochroism : Weak
Fluorescence : None

Solubility : Hydrofluoric and sulfuric acid

Magnetism : None
Radioactivity : None