Stibiconite - Sb₃O₆(OH)

Habit: Massive, botryoidal, as incrustations, may be concentrically zoned, to several centimetres thick; typically powdery, compact. White to yellow or brown Transparent to translucent, Pearly, opaline, glassy to earthy Luster.

Environment: A secondary mineral in Hydrothermal mineral deposits, formed by the oxidation of other antimony-bearing minerals, commonly stibnite, which it may entirely replace

Etymology: From the Latin for antimony, stibium, and the Greek for powder or dust, a common habit.