The form Relations of the Lead Oxychlorides, Laurionite, Paralaurionite, and Fiedlerite

Charles Palache¹

Professor of Mineralogy, Harvard University, Cambridge, Massachusetts

¹The author desires to acknowledge his indebtedness to his co-workers in this study. Dr. L. LaForge made the preliminary studies and calculated some of the tables. Dr. M. A. Peacock made some of the measurements and all of the drawings. Mr. H. Berman determined the optical properties of all three of the minerals.

Summary: New observations on laurionite, paralaurionite, and fiedlerite are presented. The separate identity of each of the first two minerals is confirmed and their homeomorphism is exhibited by a reorientation of laurionite. The form series of fiedlerite has been simplified by the choice of a new unit form. New forms are described on all three minerals. The crystallography of all three species is summarized in new angle-tables and their habits are illustrated by a series of drawings.

Mineralogical Magazine; September 1934 v. 23; no. 146; p. 573-586; DOI: 10.1180/minmag.1934.023.146.01
© 1934, The Mineralogical Society
Mineralogical Society (www.minersoc.org)