EOSPHORITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Hydrated phosphates
    Crystal system : Monoclinic
    Chemistry : MnAl(PO4)(OH)2 H2O
    Rarity : Rare

Eosphorite is a hydrated phosphate typical of pegmatites rich in phosphorus, and of certain hydrothermal veins. It forms an isomorphic series with childrenite, its iron equivalent. It takes its name from the Greek eosphoros (glow of dawn) in allusion to its frequently pink color. Eosphorite appears, like childrenite, in equant crystals, or finely tabular prismatic pyramidal crystals, striated according to elongation, frequently grouped in sheaves. It is a transparent to translucent mineral, yellow-brown to pink-red, sometimes yellowish in color.

Main photo : Eosphorite on rose quartz from Ilha claim, Taquaral, Itinga, Minas Gerais, Brazil © Rock Currier

Eosphorite from Estes Quarry, Baldwin, Maine, USA © Stephan Wolfsried
Eosphorite from Taquaral, Itinga, Minas Gerais, Brazil
Eosphorite from Dunton Gem Quarry, Maine, USA © David Busha
10 cm eosphorite from Linópolis, Minas Gerais, Brazil © Heritage Auctions

Eosphorite in the World

The Brazilian pegmatites of Minas Gerais give the most beautiful samples of eosphorite in the world : extraordinary sheaves and spherolites of crystals reaching 20 cm associated with rose quartz crystals were extracted from Lavra da Ilha, near Taquaral. The pegmatites of Araçuai or Galiléia also gave superb large sheaves of eosphorite, as did those of Mendes Pimentel (state of Espirito Santo). In the United States, the pegmatitic fields of New England have yielded good crystals, notably those of Rumford, Paris and Auburn, in Maine, and those of Palermo, in New Hampshire.

Eosphorite in France

In France, eosphorite is reported at Échassières (Allier), at Montebras (Creuse) as well as in the pegmatites of Collioure (Pyrénées-Orientales).

Twinning

Twins are known on {100} and {001}.

Fakes and treatments

No fake listed for this mineral species.


Hardness : 5
Density : 3.06 to 3.08
Fracture : Irregular to sub-conchoidal
Streak : White

TP : Translucent to transparent
RI : 1.628 to 1.679
Birefringence : 0.029 to 0.035
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Acids


Magnetism : None
Radioactivity : None