Denader 004，碳质碳黑。 令人惊叹的基质，含有巨大的铁球粒。 - 0.56 g - (1)

Denader 004 20°08'08.9"N, 4°56'22.8"W

Gao, Mali

分类：碳质陨石（CB）

History: We found the meteorite during a search in Mali and subsequently purchased from a local dealer.

Physical characteristics: Several fragments, up to a few centimeters in size, with prominently exposed brownish metal nodules in a grayish silicate matrix plus many loose spheres that weathered out.

Petrography: Metal-rich breccia composed of about 40% rounded to ellipsoidal shaped kamacite-dominated metal nodules (apparent diameter 2.5±1.3 mm, n=31) and about 60% silicate groundmass consisting of radial and finely barred chondrules (up to 4 mm in size) plus chondrule and mineral fragments in a fine-grained matrix. Metal nodules are polycrystalline and contain abundant blebby and elongated Cr-bearing troilite inclusions often decorating kamacite grain boundaries. Dominant silicates in chondrules and matrix are enstatite and forsterite with subordinate zoned olivine, ferroan low-Ca pyroxene, and aluminous diopside. Minor phases in the matrix include Cr-bearing spinel, magnetite, troilite, kamacite, taenite, and schreibersite. No refractory inclusions detected. The meteorite is moderately weathered and many metal nodules are surrounded by a thin iron hydroxide rim.

Geochemistry: forsterite: Fa2.7±0.1 (Fa2.7-2.8, n=7); zoned olivine: Fa17.9±2.5 (Fa14.7-22.0, n=7); enstatite: Fs2.0±0.1Wo0.6±0.1 (Fs2.0-2.1Wo0.5-0.6, n=7); ferroan low-Ca pyroxene: Fs19.2±0.1Wo0.6±0.2 (Fs19.1-19.3Wo0.4-1.0, n=7); aluminous diopside: Fs2.4±0.2Wo41.7±0.7 (Fs2.3-2.7Wo40.6-42.5, n=7); kamacite is Si-free and contains 5.95±0.20 wt% Ni, 0.26±0.03 wt% Co, and 0.40±0.02 wt% P, n=7 and troilite inclusions contain up to 5.6 wt% Cr.

分类：碳质陨石（CB）。高比例的硅酸盐部分（60% vs CBa 少于50%、CBb 少于30%），陨石圆粒直径（达4 mm）与 CBa 的厘米级和 CBb 的0.2-1 mm 不同，及晶粒基质的存在，以及带有分级的橄榄石和铁镁辉石，无法无歧义地归入已知亚组。

Shock stage: 低
Weathering grade: 中等
Classifier: A. Greshake, MNB.

This lot comes with certificate of authenticity.
Thanks for your interest.