ferberite

{{Infobox mineral | name = Ferberite | image = Ferberite - Panasqueira mines, Beira Baixa, Portugal.jpg | imagesize = 280px | alt = | caption = Ferberite with muscovite from Minas da Panasqueira, Beira Baixa, Portugal | category = Tungstate mineral | formula = FeWO4 | IMAsymbol = Feb | strunz = 4.DB.30 | dana = | system = Monoclinic | class = Prismatic (2/m) (same H-M symbol) | symmetry = P2/c | unit cell = a = 4.72, b = 5.7 c = 4.96 [Å]; β = 90°; Z = 2 | color = Black, dark brown in transmitted light | habit = Bladed crystals; massive | twinning = Contact or interpenetrant or lamellar twins | cleavage = Perfect on {010}; partings on {100} and {102} | fracture = Uneven | tenacity = Brittle | mohs = 4–4.5 | luster = Submetallic to metallic adamantine | streak = Brownish black | diaphaneity = Nearly to entirely opaque | gravity = 7.58 | density = | polish = | opticalprop = Biaxial (+) | refractive = nα = 2.255 nβ = 2.305 nγ = 2.414 | birefringence = δ = 0.159 | pleochroism = | 2V = Measured: 66° | dispersion = | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = | impurities = | alteration = | other = Slightly magnetic | prop1 = | prop1text = | references = }}

Ferberite is the iron endmember of the manganese–iron wolframite solid solution series. The manganese endmember is hübnerite. Ferberite is a black monoclinic mineral composed of iron(II) tungstate, FeWO4.