Emerald green crystal aggregates of the very rare tellurium mineral cesbronite from Tombstone (Tombstone District, Cochise County, Arizona, United States of America). Cesbronite has only been found in 3 localities worldwide. — Photo: David Hospital · CC BY-SA 4.0
Cesbronite
A green orthorhombic copper tellurate of Mohs hardness 3.
Intro adapted from Wikipedia (CC BY-SA).
Cesbronite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Cu₃Te⁶⁺O₄(OH)₄.
It crystallizes in the orthorhombic crystal system (space group Pbcn).
Key properties: Mohs hardness 3; specific gravity 4.45; Pale green streak; optically biaxial.
IMA symbol Ces, IMA status: approved, named in 1974.
Found as a secondary mineral in an oxidized Cu–Te–Pb sulfide deposit (Oriental mine, Mexico).
It is found associated with Argentian gold, teineite, carlfriesite, xocomecatlite (Oriental mine, Mexico); utahite, leisingite, jensenite, hematite (Centennial Eureka mine, Utah, USA).
The mineral was named to honor Dr. Fabian Cesbron (1938–), French mineralogist with the Bureau de Recherches Géologiques et Minières, Orléans, France.