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CRÁTHEUS (1950)
Iron
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DESCRIPTION:
ACHONDRITE
PLESSITIC OCTAHEDRITE
IIC
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BRAZIL - CE
1909
Iron Meteorite - Octahedrite Plessitic IIC.
PETROGRAPHY:
The specimen examined slightly weathered and the melting crust and heat change zone were lost. Mineralogically, kamacite has sub-boundaries and Neumann bands, and the hardness is 175 ± 5. Schreibersite occurs uniformly dispersed, wide, with branched polycrystalline crystals. Troilite is quite common as monocrystalline units. Pentlandite is absent. Chromite occurs as euhedral crystals, which served as a substrate for troilite and schreibersite precipitate. The plessitic matrix covers about 60% per area, mainly as an easily resolvable, but dense, flexible liquid. Source: Buchwald (1975).
GEOCHEMISTRY:
8.96% Ni, 0.3% P, 36 ppm Ga, 91 ppm Ge, 9.5 ppm Ir. Source: Buchwald (1975).
CLASSIFICATION:
When chemically attacked on its polished surface, it shows that the mass belongs to the very rare group of plessitic octahedrites, axis width 60 ± 15 µm, comprising among others Ballinoo, Kumerina and Unter Massing. Chemically, the meteorite was classified as an IIC. For more information, access the source link http://evols.library.manoa.hawaii.edu/bitstream/handle/10524/35673/vol2-Coy-Day(LO).pdf#page=5. Source: Buchwald (1975).
CLASSIFIERS:
Not reported by the Meteoritical Bulletin Database. According to Buchwald (1975), the meteorite was first studied by Curvello (1950b).
HISTORY:
There is no historical data available. When Curvello (1950b) described the metallography of the meteorite, he assumed that its material came from the 27.5 kg Cratheus mass listed by Oliveira (1931: 49). During the study by Buchwald (1975), it was discovered that the photomicrographs of Curvello and Oliveira must be of two different masses and the author borrowed Curvello's material. He was just 20g and lent it, enabling Dr. J.T. Wasson to perform a chemical analysis. The review undoubtedly establishes that Crátheus de Oliveira and Crátheus de Curvello are very different, one being of the Gibeon type, the other of the Ballinoo type. With this error, it was proposed to call Crátheus 1950 the material studied by Curvello (1950) and Crátheus 1931 the meteorite studied by Oliveira (1931). Source: Buchwald (1975).
All information that does not have a specific source was extracted from the Meteoritical Bulletin Database.
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