Mroseite

mroseite

spiroffite

denningite

zemannite

Images

Formula: CaTe4+O2(CO3)
Compound tellurite
Crystal System: Orthorhombic
Specific gravity: 4.35 measured, 4.171 calculated
Hardness: 4
Streak: White
Colour: Colourless to white
Solubility: Effervesces in cold, dilute hydrochloric acid
Environments

Hydrothermal environments

Mroseite occurs as a secondary mineral in telluride-bearing veins (Webmin).
Tellurium forms Te2O4 groups with the oxygens that are not bonded to carbon. These Te2O4 groups consist of two TeO3 pyramids with a common O-O edge. It is the TeO3 groups that make the mineral a tellurite (CM 13.383-387).

Localities

At the type locality, the Moctezuma Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico, mroseite is a very rare mineral in a hydrothermal gold-tellurium deposit. Associated minerals include spiroffite, tellurium, tellurite, denningite, zemannite and quartz (AM 60.946, HOM, Mindat).
Mroseite occurs as crude, translucent, colourless to reddish pink or brown, adamantine crystals to 6 mm and radiating masses and crusts fused with tellurite. In this association, the mineral was probably formed as a decomposition product of spiroffite. The pink coloration is due to low manganese levels (Minrec 55.6.845).
Mroseite from Moctezuma - Image

At the T.E.I. pit, Cochise County, Arizona, USA, mroseite is associated with "oboyerite" (a mixture of ottoite and plumbotellurite), choloalite and gold (HOM).

Back to Minerals