On ‘Winchite’ from the Original Locality at Kajlidongri, India

V. K. Nayak and Bernard E. Leake
Centre of Advanced Study in Geology, University of Saugar, P.O. Saugar (M.P.), 470-003, India
Department of Geology, The University, Glasgow G12 8QQ

Summary: A new analysis of the violet amphibole from the original locality where winchite came from agrees with another recent analysis in differing substantially from the original winchite composition and is (K0·17Na2·10Ca0·23)(Al0·19Ti0·00Fe31·27Fe20·01Mn0·07Mg3·34)Si8·01O22·05(OH)1·95. It is essentially a magnesio-arfvedsonite. Although it is possible that the original analysis was unreliable, evidence is given to support the alternative view that there is a wide range of blue alkali and soda calcic amphibole compositions at Kajlidongri and the name winchite should be restricted to compositions between ferri-winchite CaNaMg5Fe3+Si8O22(OH,F,Cl)2 and alumino-winchite CaNaMg5Al Si8O22(OH,F,Cl)2. X-ray, density, and optical data on the analysed mineral are given.

Mineralogical Magazine; December 1975 v. 40; no. 312; p. 395-399; DOI: 10.1180/minmag.1975.040.312.08
© 1975, The Mineralogical Society
Mineralogical Society (www.minersoc.org)