Cowlesite specimens from nine new occurrences in Northern Ireland and from eight localities previously reported in the literature, were crystal-chem. characterized. The chem. data for a total of 25 samples indicate a compn. close to the stoichiometric formula for cowlesite and a very limited compositional range. X-ray powder diffraction spectra were performed on 8 samples. The crystallog. unit cell permits proper indexing of the x-ray powder diffraction patterns as orthorhombic, with unit cell consts. close to a 23.3, b 30.6, c 25.0 Å and doubled with respect to those originally reported in the literature. The powder pattern and the TG curve are reported for an unidentified mineral species assocd. with cowlesite in one of the samples from Northern Ireland.
The crystal chemistry of cowlesites
QUARTIERI, Simona;
1992-01-01
Abstract
Cowlesite specimens from nine new occurrences in Northern Ireland and from eight localities previously reported in the literature, were crystal-chem. characterized. The chem. data for a total of 25 samples indicate a compn. close to the stoichiometric formula for cowlesite and a very limited compositional range. X-ray powder diffraction spectra were performed on 8 samples. The crystallog. unit cell permits proper indexing of the x-ray powder diffraction patterns as orthorhombic, with unit cell consts. close to a 23.3, b 30.6, c 25.0 Å and doubled with respect to those originally reported in the literature. The powder pattern and the TG curve are reported for an unidentified mineral species assocd. with cowlesite in one of the samples from Northern Ireland.Pubblicazioni consigliate
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