Potassium tecto-alumotrisilicate

AlKO₈Si₃

Chao, S HHargreaves, ATaylor, W H

Mineralogical Magazine and Journal of the Mineralogical Society (1876- 1968) (1940) 25, 498-512

a=8.6Å   b=13.02Å   c=7.22Å

α=90°   β=116.05°   γ=90°