NWA 4025 (5,166 g)
Bencubbinite with S3 W 2/3 and Fa 1,7-4,4 Fs 1,5-3,9 there were 69 individuals with a TKW of only 745,5 grams. There were no larger pieces found after several days of hunting in that area. The very special on this meteorite is, that this is only the 2nd Bencubbinite coming from NWA. This material looks very simmilar like the original Bencubbin. Not comparable with Gujba and NWA1814. Remember how hard it is to get a Bencubbinite for your collection. This is your chance to get a highly scientific piece to an extreme good price.
These pieces are all splitted individuals ( endcuts ) and all are polished, so it was not easy to do a good photo because the light reflexions of the metal.
Some of the listed individuals are still good for splitting or grinding yourselfe to see the interior.
If you like some small individuals as a sample for your collection, don´t hesitate to contact me, I have some in the size between 1 - 5 gram available.
Northwest Africa 4025
Find: August 2005
Carbonaceous chondrite (CB)
History: A total of 69 fragments were purchased in August 2005 from a dealer in Erfoud, Morocco.
Physical characteristics: The small, mostly angular fragments, totaling 745.5 g, display a rusty brown surface; fusion crust is almost absent.
Petrography: (A. Greshake, MNB) The meteorite is characterized by a high modal metal abundance of about 60–80 vol%. The silicate portion contains abundant, large (up to several millimeters) and clearly defined chondrules of different textural types including cryptocrystalline, BO, PO, and POP chondrules.
Mineral compositions and geochemistry: Olivine (Fa1.7–4.4), low-Ca pyroxene (Fs1.5–3.9), determined by EMP. Oxygen isotopes: (I. A. Franchi and R. C. Greenwood, OU) δ17O = 0.22, δ18O = 3.73, Δ17O = −1.72 (mean of 2, all ‰). Nitrogen isotopes: (I. A. Franchi and A. Verchovsky, OU) 89.8 ppm N with a bulk δ15N = 601 ‰ and a peak at 1000 °C of 1169‰.
Classification: Carbonaceous chondrite (CB); S3, moderate weathering. The meteorite is a Bencubbin-like carbonaceous chondrite (CB) based on petrography and metal/silicate ratio while O-isotopes suggest a close relation to CH chondrites.
Type specimen: A total of 20 g plus one polished thin section are at MNB. HSSH holds the main mass.
|Place of purchase:||Erfoud, Morocco|
|Classifier:||A. Greshake, MNB|
|Type spec mass (g):||20|
|Type spec location:||MNB|
|Main mass:||Hanno Strufe|