TRIPLITE

    Class : Phosphates, arsenates, vanadates
    Subclass : Anhydrous phosphates
    Crystal system : Monoclinic
    Chemistry : (Mn,Fe,Mg,Ca)2(PO4)(F,OH)
    Rarity : Fairly common

Triplite is a complex phosphate of manganese and iron that forms a continuous series with zwieselite, its iron equivalent. Low magnesium and calcium contents may appear. It is a mineral of granitic pegmatites, mainly sodolithic pegmatites where it accompanies lepidolite and triphylite. Its name comes from the Greek triplos (triple) in reference to its three cleavages. Triplite constitutes few crystals, it is usually massive, dark brown to brown, sometimes salmon to reddish when it contains little iron. Like many manganese carbonates and phosphates, it weathers black, releasing manganese oxides and generating a series of secondary hydrated manganese phosphates. It is occasionally cut into gemstones and cabochons.

Main photo : Triplite from Shigar Valley, Pakistan © Rob Lavinsky

Triplite from Namlook Mine, Dassu, Pakistan © Rob Lavinsky
20 cm triplite from Chão do Castanheiro, Viseu, Portugal © Rui Nunes
1.03 ct faceted triplite from Brazil Faceted
Triplite in cabochon of 66.50 ct from Peru

Triplite in the World

Triplite is found in impressive masses, exceeding one meter, in the pegmatites of Blesberg and Straussheim (Northern Cape, South Africa), and in those of El Criollo (Cordoba province, Argentina). Many American pegmatites from California (Pala), Connecticut, Colorado and Arizona have also yielded appreciable masses of several kilograms.

Triplite in France

In France, the lepidolite pegmatites of St-Sylvestre and Chanteloube, in the Ambazac mountains (Haute-Vienne), have yielded centimeter-sized cleavable masses of triplite.

Twinning

No twin known for this mineral species.

Fakes and treatments

No fakes listed for this mineral species.


Hardness : 5 to 5.5
Density : 3.5 to 3.9
Fracture : Irregular to conchoidal
Streak : White to brown

TP : Translucent to transparent
RI : 1.650 to 1.691
Birefringence : 0.030
Optical character : Biaxial -
Pleochroism : Visible
Fluorescence : None

Solubility : Acids

Magnetism : NoneRadioactivity : None