VARISCITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Hydrated phosphates
    Crystal system : Orthorhombic
    Chemistry : AlPO4 2H2O
    Rarity : Fairly common


Variscite is a secondary phosphate present mainly in aluminous sedimentary formations transformed under the action of meteoric waters or hydrothermalism. Aluminum can be replaced by Fe3+ thus constituting a continuous series with strengite, which explains the unusual red tint of some specimens. This mineral owes its name to its region of discovery : Variscia, currently renamed Vogtland (Germany). The crystals of this mineral species are extremely rare, very small, and present a distinct octahedral facies. Variscite almost exclusively forms nodules (up to 30 cm in diameter) and cryptocrystalline masses of a beautiful pale green to deep green, revealing after sawing growth figures in concentric rings. Its density is quite low (2.6 on average). Mixed with wardite, variscite provides an aesthetic ornamental stone sometimes used in decoration (Utah). It also seems that in the past it benefited from the use of adornment : the pearls discovered in the Celtic tomb of Mané-er-Hroec'h in Locmariaquer (Morbihan, France) are in variscite, the color of which strongly recalls that of turquoise.

Variscite cabochon
39.00 ct variscite from Australia
Variscite cabochon
21.00 ct variscite from Australia
Variscite cabochon
15.60 ct variscite from Australia
Variscite crystals on wavellite
Variscite on wavellite rods from Echassières, Allier, France

Variscite in the World

The best specimens come from the Little Green Monster mine, near Fairfield, Utah, which produced nodules up to 30 cm in diameter, with a concentric concrete texture with shrinkage cracks. Although down from Little Green Monster, neighboring Utah deposits, and some in Arizona (Bisbee) and Arkansas (Avant), also provided high quality decimeter nodules. The only notable microcrystals come from the Iron Monarch mine, near Iron Knob (Australia). Variscite is known in many localities in Europe (Messbach, Germany ; St Austell, England ; Cerhovice, Bohemia, etc...), but only Palazuelo (Province of Zamora, Spain) provided masses usable in decoration.

Variscite in France

In France, the Pannecé quarry (Loire-Atlantique) produced masses with a pisolithic texture of several kilos, associated with wavellite and miniyulite. The kaolin quarries at Echassières (Allier) also provided transparent infra-millimeter microcrystals, sometimes on wavellite needles.

Twinning

No twinning known for this mineral species.

Fakes and scams

No fake inventories for this mineral species.



Hardness : 3.5 to 4.5
Density : 2.6
Fracture : Irregular
Trace : White



TP : Opaque to translucent
RI : 1.563 to 1.594
Birefringence : 0.031
Optical character : Biaxial -
Pleochroism : Not observable
Fluorescence : Green


Solubility : Hydrochloric acid and caustic soda

Magnetism : None
Radioactivity : None