Single crystal aggregate of the rare mineral wonesite from Vermont (Post Pond Volcanics, Norwich, Windsor County, Vermont, United States of America). Ex. Erich Laskowski collection (USA). — Photo: David Hospital · CC BY 4.0
Wonesite
Wonesite is an IMA-recognized mineral species in the silicate class, with the chemical formula (Na,K, )(Mg,Fe,Al)₆(Si,Al)₈O₂₀(OH,F)₄.
It crystallizes in the monoclinic crystal system (space group C-1). It is a member of the Mica, Clay structural group.
Key properties: specific gravity 2.89; optically biaxial.
IMA symbol Wns, IMA status: approved, named in 1979.
Found in metavolcanics with high Mg: Fe, moderate sodium, and very little calcium, metamorphosed at an estimated 535 ± C.
It is found associated with Phlogopite, talc, anthophyllite, cordierite, gedrite, chlorite, quartz.
The mineral was named to honor petrologist David R. Wones (1932–1984), Professor of Geology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA.