Atacamite , Pseudoboleite , Schwartzembergite Locality: Caracoles , Sierra Gorda District, Tocopilla Province , Antofagasta Region , Chile ( Locality at mindat.org ) Size: small cabinet, 7.6 x 4.7 x 3.1 cm Percylite and Schwartzembergite, and Atacamite A beautiful specimen of this rare mineral combination: apparently a strange admixture of Boleite & Pseudoboleite that is probably soon to be disallowed as a species name. Still, highly unusual, and with a color all its own. To be frank, I haven't confirmed the presence of Schwartzembergite which is supposed to be a minute red stain...but I am pricing this, thus, as simply an attractive percylite and if you can find the Schwartzembergite, that is a bonus. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Schwartzembergite
Schwartzembergite is an IMA-recognized mineral species in the halide class, with the chemical formula Pb²⁺₅H₂I³⁺O₆Cl₃.
It crystallizes in the tetragonal crystal system (space group I4/mmm).
Key properties: Mohs hardness 2–2.5; specific gravity 5.7–7.09; Straw-yellow streak; Adamantine luster; optically uniaxial.
IMA symbol Swb, grandfathered status — known before the IMA’s founding, named in 1868.
A rare secondary mineral formed in the oxidized zone of hydrothermal polymetallic deposits in an arid climate.
It is found associated with Cerussite, anglesite, paralaurionite, boleite, seeligerite.
The mineral was named to honor Dr. Schwartzemberg [probably Dr. Adolf Emilio Schwarzenberg (1826–1907)], assayer, Copiapó, Chile, who first called attention to the mineral.