Unit Cell and Space Group of Larsenite, PbZnSiO₄

Larsenite from Franklin, New Jersey was described in 1928 by Palache, Bauer, and Berman, and a summary description was given by Palache in 1935. On morphological and chemical data, the mineral was placed in the Olivine Group and has been so accepted by later writers. No singlecrystal or powder x-ray diffraction work has been reported thus far. Recently, samples of larsenite were supplied by the Harvard Mineralogical Museum to Dr. Heinrich Neumann of the University of Oslo, who drew our attention to the fact that powder photographs of the mineral are not of the general olivine type.