Cervantite

Formula: Sb3+Sb5+O4
Simple oxide, dimorph of clinocervantite
Specific gravity: 6.64
Hardness: 4 to 5
Streak: Light yellow, white
Colour: Yellow, off-white, reddish-white; colourless in transmitted light
Environments:

Hydrothermal environments

Cervantite is a secondary mineral formed from the oxidation of stibnite, and commonly found as pseudomorphs after it and associated with it.

At Semsa, Algeria, cervantite occurs with valentinite.

At the Zhenwei (Zhenxu) antimony-gold deposit, Shanglin county, Guangxi, China, cervantite occurs in the upper oxidation zone, together with kermesite.

At the Xikuangshan antimony deposit, Lengshuijiang county, Hunan, China, cervantite occurs in the oxidation zone together with valentinite, stibiconite, kermesite and senarmontite.