Ureyite, NaCrSi2O6: A New Meteoritic Pyroxene

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Science  13 Aug 1965:
Vol. 149, Issue 3685, pp. 742-744
DOI: 10.1126/science.149.3685.742


The new mineral NaCrSi206 (ureyite) has been found as rareemeraldgreen grains in the iron meteorites Coahuila, Toluca, and Hex River Mountains. X-ray studies of the natural and synthetic material have established that the mineral is isostructural with jadeite, NaAlSi206. Indexed data for powder patterns obtained by x-ray diffraction and precise cell dimensions are given for the Cr, Fe, and Al members of the jadeite group. Unlike jadeite, a high-pressure phase, ureyite can be synthesized from melts at 1-atmosphere pressure.