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Formula: HgSe
Selenide, sphalerite group, forms a series with
metacinnabar, selenium- and
mercury- bearing mineral
Crystal System: Isometric
Specific gravity: 8.19 to 8.47 measured, 8.239 calculated
Hardness: 2½
Streak: Greyish black
Colour: Steel-grey to black
Common impurities: Cd,S,Pb
Environments
Tiemannite is found in hydrothermal veins associated with the selenides
clausthalite, eucairite,
naumannite, klockmannite and
umangite, and also metacinnabar,
galena, sphalerite,
baryte, manganese oxides and
calcite
(HOM).
Localities
At the Tumiñico Mine, Sierra de Cacho, Villa Castelli, General Lamadrid department, La Rioja Province, Argentina,
a selenide vein-type assemblage contains a variety of minerals, including
berzelianite, brodtkorbite, cadmoselite,
chaméanite, crookesite,
eskebornite, eucairite,
ferroselite, hakite,
klockmannite,
trogtalite-krut'aite,
tiemannite, tyrrellite,
umangite and uraninite. The
selenides occur as veinlets, as impregnations and as massive ores in
calcite veins, and are hosted by altered
amphibolites
(CM 40.225-237)
At the type locality, St Lorenz Mine, Burgstatt veins, Clausthal-Zellerfeld, Goslar, Lower Saxony, Germany, massive
tiemannite
is separated
from chalcopyrite by a calcite
vein
(AM 35.337-364).
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