ИСТИНА

The new unnamed mineral was discovered at first in Dhofar 225, metamorphosed carbonaceous chondrite of CM type, recovered in the desert of Oman [1]. This meteorite possibly belongs to the Yamato-group carbonaceous chondrites (CY) [2,3]. The meteorite contains several assemblages of minerals including the new mineral, Ca,Fe-oxysulfide, (Ca,Fe-Oxs) small rare grains of troilite, or sometimes pyrrhotite and Fe,Ni-metal [1]. Whole assemblages are surrounding by a fine-grained accretion dust mantle and by fine-grained phyllosilicate matrix. Phyllosilicates of initially serpentine composition were dehydrated during thermal events on the meteorite parent body that was supported by identification and comparison of crystal structures of natural and experimentally heated phyllosilicates [1]. Authors in [4] reported recently artificial mineral phase of similar composition of Ca,Fe-Oxs. This phase was obtained during laboratory heating experiments of the very altered CM chondrite ALH 83100. The authors proposed that the presence of the artificial Ca,Fe-Oxs within Ca-rich patches of ALH 83100 matrix suggests that it is a by-product of the calcination of calcite, with the iron and sulphur possibly coming from the breakdown of minerals including phyllosilicates and tochilinite. Such an origin would constrain the formation temperature of Ca,Fe-Oxs - between ~700o C (the calcination threshold of calcite) and 800oC. Here we present results on EDS-EPMA, and BSED investigations of natural and synthetic Ca,Fe-Oxs; information will be submitted to the Commission on New Minerals, Nomenclature and Classification.