wöhlerite

{{Infobox mineral|boxbgcolor=#dfb73c|image=Wöhlerite,_Amphibole_Supergroup,_Microcline-593206.jpg|formula=NaCa2(Zr,Nb)(Si2O7)(O,OH,F)2| IMAsymbol = Wöh|strunz=9.BE.17|system=Monoclinic|dana=56.2.4.5|class=H-M Symbol: 2 Sphenoidal|symmetry=P21|unit cell=764.21|color=Honey yellow, wine yellow to sulfur yellow, light to dark yellow, brown, gray|twinning=Twin planes common on {010}|cleavage=Distinct on {010} Poor on {100}, {110}|fracture=Irregular, uneven, splintery|tenacity=Brittle|mohs=5.5 – 6|luster=Vitreous|opticalprop=Biaxial (−)|refractive=nα = 1.700 – 1.705 nβ = 1.716 – 1.720 nγ = 1.726 – 1.728|birefringence=0.026|pleochroism=Weak|2V=Measured: 70°–77° Calculated: 70° to 76°|dispersion=Weak r > v|fluorescence=None|streak=Pale yellow|gravity=3.40 – 3.44|diaphaneity=Transparent, translucent}}

Wöhlerite, also known as woehlerite or wohlerite, is a member of the Wöhlerite group. It was named after German chemist Friedrich Wöhler. It was first described by Scheerer in 1843, but the crystal structure was only solved by Mellino & Merlino in 1979. Once approved, it was grandfathered by the IMA.