wüstite

{{Infobox mineral | name = Wüstite | category = Oxide mineral | boxwidth = | boxbgcolor = | image = Wüstite-110970.jpg | imagesize = 260 | caption = | formula = FeO | IMAsymbol = Wüs | molweight = | strunz = 4.AB.25 | color = Greyish white to yellow or brown; colorless in thin section | habit = Pyramidic, prismatic | system = Cubic | class = Hexoctahedral (mm) H–M symbol: (4/m 2/m) | symmetry = Fm3m (no. 225) | twinning = | cleavage = {001} perfect | fracture = Subconchoidal to rough | mohs = 5–5.5 | luster = | refractive = 1.735–2.32 in synthetic crystals | opticalprop = | birefringence = | pleochroism = None | streak = | gravity = 5.88 | density = 5.7 g/cm3 | melt = | fusibility = | diagnostic = | solubility = Soluble in dilute HCl | diaphaneity = | other = Forms solid solution with periclase }}

thumb|Crystal structure of Wüstite