Mineral description : Triphylite

Triphylite from Varuträsk. Brown on weathered surfaces. Fresh to the left.

Mineral class	Phosphates : Amblygonite - Pharmakosiderite group.
Chemical formula	Li(Fe,Mn)PO4
Crystal system	Orthorombic
Habitus	Rarely as crystals and then never well crystallised. Often as cleavable masses.
Cleavage	Basally perfect, imperfect in two directions. All cleavages are at right angles to each other.
Hardness	4-5
Density	3.58
Color	Pale gray to greenish gray on fresh surfaces.
Streak	White to grayish white.
Luster	Resinous to vitrous.
Description
Occurance	In lithium pegmatites.
Associates	Vivianite, ferrisicklerite, heterosite, cleavelandite.
Notes	Often with an surfaces of dark blue to black vivianite. Oxidised triphylite gets a yellow to dark brown surface. Often with transformation products of ferrisicklerite and heterosite.
Locations	A not so common mineral in Sweden, but a few localities exists. Varuträsk, Västerbotten. The most abundant iron phosphate, found in coarse aggregates and nodules. Norrö, Stockholm archipelago.

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