Table of Contents
International Journal of Mineralogy
Volume 2014, Article ID 287069, 6 pages
http://dx.doi.org/10.1155/2014/287069
Research Article

“Mohsite” of Colomba: Identification as Dessauite-(Y)

1Dipartimento di Scienze della Terra, Via Tommaso Valperga Caluso 35, 10125 Torino, Italy
2Associazione Micromineralogica Italiana, Via San Pietro 55, 10073 Devesi-Ciriè, Torino, Italy
3Museo Regionale di Scienze Naturali, Via Giovanni Giolitti 36, 10123 Torino, Italy

Received 11 November 2013; Revised 6 March 2014; Accepted 20 March 2014; Published 8 April 2014

Academic Editor: Elena Belluso

Copyright © 2014 Erica Bittarello et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

During a reorganization of the mineralogical collection of Turin University, old samples of the so-called mohsite of Colomba were found. “Mohsite” was discredited in 1979 by Kelly et al., as a result of some analyses performed on the equivalent material coming from the French region of Hautes-Alpes, but the original samples found in similar geological setting in Italy were lost and never analysed with modern equipment. After more than a century, the rediscovered samples of Professor Colomba were analysed by means of SEM-EDS analysis, microRaman spectroscopy, and X-ray diffraction. The results have demonstrated that the historical samples studied by Colomba are Pb-free dessauite-(Y), and pointed to an idealized crystal chemical formula (Sr0.70Na0.25Ca0.09)Σ=1.04 (Y0.62U0.18Yb0.09Sc0.08)Σ=0.97   (Ti12.66 )Σ=17.70O38 and unit-cell parameters a = 10.376(3) Å, c = 20.903(6) Å, and V = 1949(1) Å3.