Sampleite (blue) with atacamite (green), La Farola mine, Cerro Pintado, Las Pintadas district, Tierra Amarilla, Copiapó Province, Atacama Region, Chile. The image field is 1 cm wide — Photo: Aulacopalpus256 · CC BY-SA 4.0
Sampleite
A blue-green sodium-calcium-copper phosphate-chloride described in 1942 from Chuquicamata, Chile.
Intro adapted from Wikipedia (CC BY-SA).
Sampleite is an IMA-recognized mineral species in the phosphate class, with the chemical formula NaCaCu₅(PO₄)₄Cl·5H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 4; specific gravity 3.2; Pearly on {010} luster; refractive index 1.662; optically biaxial.
IMA symbol Smp, grandfathered status — known before the IMA’s founding, named in 1942.
A rare mineral found in the oxidized zone of copper deposits in arid climates; in caves, derived from copper sulfides in the cave walls and phosphate from bat guano.
It is found associated with Atacamite, libethenite, pseudomalachite, torbernite, chrysocolla, gypsum, calcite, jarosite.
In honor of Mat Sample, Mine Superintendent, Chuquicamata, Chile.