How do I identify Triphylite?

Triphylite can be identified by its hardness of 4 on the Mohs scale, Brown-green color. Look for these key characteristics when examining specimens.

What color is Triphylite?

Triphylite typically appears in Brown-green, light green-gray, may appear blue-gray, colourless to pale yellow in transmitted light. Color can vary depending on impurities and formation conditions.

How hard is Triphylite?

Triphylite has a hardness of 4 on the Mohs scale. This gives it moderate hardness.

Triphylite

A variety of Minerals

What is Triphylite?

Triphylite is a lithium iron(II) phosphate mineral with the chemical formula LiFePO4. It is a member of the triphylite group and forms a complete solid solution series with the lithium manganese(II) phosphate, lithiophilite. Triphylite crystallizes in the orthorhombic crystal system. It rarely forms prismatic crystals and is more frequently found in hypidiomorphic rock. It is bluish- to greenish-gray in color, but upon alteration becomes brown to black.

Triphylite Market Value Calculator

Estimate the market value of Triphylite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Triphylite Localities Map

See where Triphylite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Characteristics of Triphylite

Triphylite is soluble in hydrochloric and sulfuric acid. Under a blowpipe, it melts to form a dark gray, magnetic ball. Over time, the mineral undergoes alteration by oxidation, increasing the oxidation state of iron from +2 to +3 and allowing the lithium to escape, forming heterosite, FePO4. Triphylite forms a complex solution series with lithiophilite, LiMnPO4, so that natural sources of triphylite usually contain manganese. The structures of members within this series are similar to olivine-type silicates.

Composition of Triphylite

Triphylite crystallizes in an orthorhombic crystal system. The lithium coordinates to six oxygen atoms in a distorted octahedron. Likewise, the iron centers are octahedrally coordinated. The structure contains isolated phosphate tetrahedra.

Quick Facts

Physical Properties

Color: Brown-green, light green-gray, may appear blue-gray, colourless to pale yellow in transmitted light
Hardness (Mohs): 4
Density: 3.562 g/cm³
Streak: Colorless to grayish white