Outstanding perfect emerald green crystal of the extremely rare tellurite mineral jensenite from one of the only three known localities worldwide (Centennial Eureka Mine, Eureka, Tintic, Juab County, Utah, United States of America). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Jensenite
Jensenite is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula Cu²⁺₃Te⁶⁺O₆·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/n).
Key properties: Mohs hardness 3–4; specific gravity 4.76; Green streak; Adamantine luster.
IMA symbol Jen, IMA status: approved, named in 1994.
Very rare in an oxidized Cu–Te-bearing sulfide deposit.
It is found associated with Mcalpineite, xocomecatlite, leisingite, cesbronite, quartz.
The mineral was named to honor Martin C. Jensen (1959–), Reno, Nevada, USA, student of the mineralogy of Utah and Nevada, USA, who collected the first specimens.