Formula: Pb(UO2)(Te4+O3)2
Specific gravity: 5.73
Hardness: 3
Colour: Bright orange to dark orange
Solubility: Readily soluble in dilute hydrochloric acid and in dilute sodium hydroxide

Hydrothermal environments

Moctezumite is a secondary mineral in tellurium-bearing ores (Webmin). Pseudomorphs of schmitterite after moctezumite have been found (Dana).


The type locality is the Moctezuma Mine, Moctezuma, Moctezuma Municipality, Sonora, Mexico. The mine is an epithermal (shallow depth, low temperature) quartz vein containing gold with high contents of tellurium. Although the mine workings went below the water table, oxidised vein material was still found mixed with unoxidised primary minerals. The unoxidized ore was composed of quartz, baryte, fluorite, pyrite and native tellurium. The oxidised ore contained, in very minor amounts, gold, tellurite, paratellurite, emmonsite, chalcomenite, a copper selenide, hydrated iron oxides, manganese oxides, native selenium, tetradymite, altaite, cinnabar and wulfenite.
Moctezumite is a rare secondary mineral occurring as minute blades and rosettes in fractures and vugs in the oxidised zone of the quartz vein with baryte containing gold and tellurium minerals associated with the quartz. The largest crystal of moctezumite at the time of discovery was 3 mm × 1 mm × 0.2 mm. Associated minerals were baryte, pyrite, emmonsite, limonite and other unnamed tellurites. (AM 50.1158-1163, R&M 93.5.466-471). Other associated minerals include schmitterite, zemannite, burckhardtite and tellurite (HOM, Dana).

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