The mineral purpurite is a manganese phosphate with the chemical formula Mn3+PO4. The brown-black, dark red, but typically purple-purple purpurite has a dull sheen, a red stripe color and the mineral has perfect cleavage along the crystal planes [100] and [001]. The crystal system is orthorhombic. Purpurite has an average density of 3.4, its hardness is 4 to 5 and the mineral is not radioactive. The name of the mineral purpurite is derived from the Latin word purpureus, meaning "purpur". Purpurite is a phosphate that forms a series with heterosite. The type location is the Faires tin mine, Kings Mount, Gaston county, North Carolina, United States. The mineral is further found in Newry, Maine, United States.