Formula:  Mn³⁺(PO₄)

Species:

Colour: Dark purple to purplish red

Lustre: Dull, Earthy

Hardness: 4 – 4½

Specific Gravity: 3.2 – 3.4

Crystal System: Orthorhombic

Member of: Triphylite Group

Name: Named in 1905 by Louis C. Graton and Waldemar T. Schaller from the Latin “purpura” in allusion to its colour.

Type Locality: Faires Mine, Kings Mountain, Gaston Co., North Carolina – USA

Isostructural with: Heterosite, Lithiophilite, Olivine Group, Triphylite;Triphylite Group, Heterosite-Purpurite Series
Purpurite is the trivalent Mn-dominant, Li-deficient oxidation product of lithiophilite. The species of the Heterosite-Purpurite Series are secondary minerals formed by oxidation of iron and or manganese with the simultaneous leaching of lithium, primarily from their respective parent species, lithiophilite and triphylite. Intermediate alteration products are part of a continuous process of alteration: Ferrisicklerite and Sicklerite, are intermediate between unoxidized and unleached end-members and the completely leached and appropriately oxidized end-products, but may not be valid species. The Mn:Fe value has not been observed to vary much from the primary lithiophilite to the secondary purpurite. Purpurite is far less common than its look-alike species, heterosite. Purpurite is frequently artificially colored bright purple through acid etching.