NWA 869 陨石，L3-6级。 最著名的球粒陨石。 - 51.4 g

Northwest Africa 869
Find: 2000 or 2001
Physical characteristics: Most samples are individual meteorites but some fragments (mostly >1 kg) also occur. In most cases the fusion crust has been polished or ablated by wind erosion. Many samples are more severely affected and show faces with deep wind erosion features. Fracture faces, formed by ground collision, show a typical gray-green color and sometimes visible brecciation (light and/or dark clasts). Due to the coarseness of this breccia, there are some stones that consist of only a single lithology.

Petrography: This chondritic breccia consists of about 75 vol% matrix with unequilibrated and equilibrated L-chondrite clasts (up to 5.5 cm), some of which display shock-darkening. Impact melt-rock clasts, themselves either clast-free or clast-poor, also occur and are strongly depleted in Fe,Ni metal and sulfide.

Geochemistry: Northwest Africa 869 is a regolith breccia, containing solar noble gases and preirradiated lithologies. Olivine in lithic clasts: Fa0.2-49.2; olivine in matrix: Fa10.3-29.3; low-Ca pyroxene in lithic clasts: Fs2.1-35.9; low-Ca pyroxene in matrix: Fs7.0-23.9. Bulk oxygen isotopes: δ17O = 3.52; δ18O = 4.67; Δ17O = 1.09 per mil. Terrestrial age: 4.4 ± 0.7 ka. Preatmospheric meteoroid size and mass: 225 ± 25 cm, 120-230 T.

Classification: Because NWA 869 contains unequilibrated clasts, its classification is revised to L3-6.

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