Pseudomalachite Locality: Morenci , Copper Mountain District (Clifton-Morenci District), Shannon Mts, Greenlee County , Arizona , USA ( Locality at mindat.org ) Size: small cabinet, 7.9 x 5.3 x 4.3 cm Pseudomalachite A druse of vivid, bright green, spherules, of pseudomalachite, covers the nooks and crannies of brown, blocky, limonite. This green color is more intense than that of malachite. One is a phosphate, the other carbonate....don't confuse the rare with the common! — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Pseudomalachite
Copper phosphate named 'false malachite' for its deceptive green color.
Intro adapted from Wikipedia (CC BY-SA).
Pseudomalachite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Cu₅(PO₄)₂(OH)₄.
It crystallizes in the monoclinic crystal system (space group P2_1/c).
Key properties: Mohs hardness 4.5–5; specific gravity 4.15–4.35; Pale green to pale bluish green streak; Vitreous to resinous luster; refractive index 1.838; optically biaxial.
IMA symbol Pmlc, grandfathered status — known before the IMA’s founding, named in 1813.
Found as a secondary mineral in the oxidized zone of hydrothermal copper deposits.
It is found associated with Libethenite, malachite, cornetite, chrysocolla, quartz.
Its name comes from the Greek for false, as the mineral closely resembles malachite.