NWA 7325 (possible pairing) – Ungrouped Achondrite

27.83g Crusted (~30%) Fragment



These stunning photos have not been retouched at all except to crop them. There is no color manipulation and represent the true colors of NWA 7325 as seen under studio lighting (5500K).

This stone is being represented as a possible pairing to NWA 7325. Upon request, scientific analysis can be conducted to confirm the pairing.

This stone weighs 27.83g and is for sale. Serious offers can PM me or email me. Institutional sales are welcome as well. The stone is in my possession and ready to ship.

Description from the MetBull:
Physical characteristics: A group of 35 very fresh, dark greenish stones (total 345 g), several of which have partial remnant chartreuse-colored fusion crust. This material is notable for the characteristic “frosty” luster of the plagioclase and bright green color of the clinopyroxene.

Petrography: (A. Irving and S. Kuehner, UWS): The studied specimen has an overall plutonic igneous (possibly cumulate) texture. It is a medium-grained aggregate of Al-Cr-bearing diopside, calcic plagioclase and lobate (possibly resorbed) grains of forsterite, with accessory Cr-bearing iron sulfide (probably troilite), very sparse ferrochromite, kamacite and taenite, and rare eskolaite (associated with Cr-Fe sulfide). In thin section the untwinned plagioclase is birefringent, but the levels of birefringence are less than normal and variable on a fine scale (suggesting the existence of compositional and/or structural microdomains); there also are sparse vesicles (suggesting at least partial melting). The pyroxene exhibits at least two sets of polysynthetic twin lamellae, which resemble those produced by moderately high shock.

Geochemistry: Clinopyroxene (Fs1.1-2.6 Wo45.1-44.5, FeO/MnO = 12-21, Al2O3 = 2.6-2.8 wt.%, Cr2O3 = 1.0 wt.%), plagioclase (An88.1-89.2Or0.0), olivine (Fa2.7-2.8, FeO/MnO = 30-36, CaO = 0.27-0.32 wt.%, Cr2O3 = 0.32-0.35 wt.%). Bulk composition (G. Chen, UAb): analyses of representative bulk wire-saw cutting dust by ICP-MS gave: (in ppm) La 0.15, Ce 0.34, Nd 0.16, Sm 0.05, Eu 0.58, Gd 0.05, Hf 0.44, Th 0.27. Oxygen isotopes (K. Ziegler, UNM): laser fluorination analyses of acid-washed subsamples gave, respectively δ17O = 3.214, 3.670, 3.249; δ18O = 7.566, 8.204, 7.957; Δ17O = -0.781, -0.662, -0.952 per mil [for TFL slope of 0.528].

Classification: Achondrite (ungrouped). The combination of highly magnesian mafic silicates and highly calcic plagioclase with chromium-bearing sulfides is unique among achondrites, and the specimen is highly depleted in most trace elements.



PP-NWA7325-27g83-f-lr  PP-NWA7325-27g83-e-lr  PP-NWA7325-27g83-c-lr  PP-NWA7325-27g83-b-lr  PP-NWA7325-27g83-h-lr  PP-NWA7325-27g83-g-lr