Scorodite - Fe³⁺AsO₄·2H₂O

Habit: Pale leek green or gray green to brown, colorless, bluish, violet or yellow. Crystals pyramidal, tabular or prismatic; commonly crystalline crusts or may be porous, sinterlike, earthy or massive. Vitreous to subadamantine or subresinous luster; semitransparent to transparent in crystals. Greenish white streak.

Environment: A secondary mineral formed by oxidation of arsenic-bearing sulfides.

Etymology: From the Greek word for "garlic-like," in reference to its odor when heated.