Numerous mall octahedra of a black, brittle, magnetic mineral were found in calciphyre and brucite marble, occurring in the northern part of the exocontact zone of the Kondyor ultramafic-alkalic massif (south-eastern part of the Aldan Shield, 250 km north west of sea port Ayan). Their composition co...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.604.5097 http://www.minersoc.org/pages/Archive-MM/Volume_56/56-384-385.pdf |
| Summary: | Numerous mall octahedra of a black, brittle, magnetic mineral were found in calciphyre and brucite marble, occurring in the northern part of the exocontact zone of the Kondyor ultramafic-alkalic massif (south-eastern part of the Aldan Shield, 250 km north west of sea port Ayan). Their composition corresponds to the group from titanium magnesioferrite (11.53 % TiO2) to titanium-rich magnesian spinel (27.34 % TiO2), similar to spinellide found in Greenland (Gittins et al., 1982) and in Iraq (A1-Hermezi, 1985) and approved by the Commission on New Minerals as a new mineral named qandilite. Hardness, specific gravity, and reflectance of Kondyor qandilite are similar to those of the Iraq mineral. Peaks of IR-absorption spectra are equal to 580-590 cm-1 (vl) and 431-438 cm- ~ (v2). There is a positive correlation between lattice parameters and the amount of Mg2TiO4: from 8.368 A at 26.6 % to 8.429 ~ at 60.4%. Kondyor qandilite crystallized together with geikielite, oxidized alumina spinel (8.55 % Fe203, ftotal: 16.5%), periclase, and forsterite. |
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