Purple paracoquimbite. From: Alcaparrosa Mine, Cerritos Bayos, El Loa Province, Antofagasta Region, Chile. — Photo: David Hospital · CC BY-SA 4.0
Paracoquimbite
Paracoquimbite is an IMA-recognized mineral species in the sulfate class, with the chemical formula Fe³⁺₄(SO₄)₆(H₂O)₁₂·6H₂O.
It crystallizes in the hexagonal crystal system (space group R-3). It is a member of the Coquimbite structural group.
Key properties: Mohs hardness 2.5; specific gravity 2.11; Vitreous luster; optically uniaxial.
IMA symbol Pcoq, IMA status: approved, named in 1933.
A rare mineral formed in the oxidized zone of pyritic hydrothermal orebodies, especially in arid regions.
It is found associated with Coquimbite, römerite, szomolnokite, quenstedtite, ferricopiapite, rozenite, voltaite.
Its name comes from the Greek for near and its relation to coquimbite.