An Example of Porphyry-Quartz, from the Esterel Mtns., France, Twinned on Face (1012)

Julien Drugman

Mineralogical Magazine; March 1922 v. 19; no. 96; p. 295-300; DOI: 10.1180/minmag.1922.019.96.02
© 1922, The Mineralogical Society
Mineralogical Society (www.minersoc.org)