Meteorite**NWA 13636, Basaltic Eucrite, Unbrecciated**1.213 Grams Slice! RARE!!

Description

Hello up for sale is NWA 13636, classified as a very rare Basaltic Eucrite, Unbrecciated. This beautiful slice weighs 1.213 grams and has a fine-grained basaltic texture, mirror polish to both sides with approximately 50% pyroxene and 40% plagioclase. This meteorite was found in 2018 near Bechar, Algeria and consists of only 5 pieces weighing of 806.92 grams. This is a pretty rare type of Eucrite and has a very unique look to it, comes with display case and COA card. Thanks for your interest and take care.
Unbrecciated Eucrites are very rare and important to science, there are many studies relating to these type of meteorites.
Here is one Abstract “ Wiley online Library”
Petrologic insights from the spectra of the unbrecciated eucrites: Implications for Vesta and basaltic asteroids
Abstract– We investigate the relationship between the petrology and visible–near infrared spectra of the unbrecciated eucrites and synthetic pyroxene–plagioclase mixtures to determine how spectra obtained by the Dawn mission could distinguish between several models that have been suggested for the petrogenesis of Vesta’s crust (e.g., partial melting and magma ocean). Here, we study the spectra of petrologically characterized unbrecciated eucrites to establish spectral observables, which can be used to yield mineral abundances and compositions consistent with petrologic observations. No information about plagioclase could be extracted from the eucrite spectra. In contrast, pyroxene dominates the spectra of the eucrites and absorption band modeling provides a good estimate of the relative proportions of low‐ and high‐Ca pyroxene present. Cr is a compatible element in eucrite pyroxene and is enriched in samples from primitive melts. An absorption at 0.6 μm resulting from Cr3+ in the pyroxene structure can be used to distinguish these primitive eucrites. The spectral differences present among the eucrites may allow Dawn to distinguish between the two main competing models proposed for the petrogenesis of Vesta (magma ocean and partial melting). These models predict different crustal structures and scales of heterogeneity, which can be observed spectrally. The formation of eucrite Allan Hills (ALH) A81001, which is primitive (Cr‐rich) and relatively unmetamorphosed, is hard to explain in the magma ocean model. It could only have been formed as a quench crust. If the magma ocean model is correct, then ALHA81001‐like material should be abundant on the surface of Vesta and the Vestoids.
Northwest Africa 13636
Basic information Name: Northwest Africa 13636
This is an OFFICIAL meteorite name.
Abbreviation: NWA 13636
Observed fall: No
Year found: 2018
Country: Algeria
Mass:help 807 g
Classification
history:
Recommended: Eucrite-unbr
This is 1 of 102 approved meteorites classified as Eucrite-unbr.
Search for other: Achondrites, Eucrites, and HED achondrites
Comments: Approved 16 Dec 2020
Writeuphelp
Writeup from MB 109:
Northwest Africa 13636 (NWA 13636)
Algeria
Purchased: 2018
Classification: HED achondrite (Eucrite, unbrecciated)
History: Reportedly found near Bechar, Algeria in 2018.
Physical characteristics: Five identically appearing stones found together. All stones have smooth sand blasted exterior surfaces. Saw-cut surfaces reveal a gray, fine-grained basaltic texture.
Petrography: (C. Agee, UNM) Microprobe examination of a polished mount shows a intergranular texture with approximately 50% pyroxene and 40% plagioclase. Plagioclase grains are lath-shaped up to 500 μm in length. Accessory phases include chromite, Cr-rich ilmenite, and silica.
Geochemistry: (C. Agee, UNM) Low-Ca pyroxene Fs53.7±3.6Wo15.1±5.0, Fe/Mn=33±1, n=16; plagioclase An86.8±0.9Ab12.4±0.9, n=8.
Classification: Basaltic eucrite, unbrecciated
Specimens: 21.9 g on deposit at UNM, Matthew Stream holds 278.92 g, John Divelbiss holds 595.6 g stone.
Data from:
MB109
Table 0
Line 0:
Place of purchase: Morocco
Date: P 2018
Mass (g): 806.92
Pieces: 5
Class: Eucrite-unbr
Shock stage: low
Weathering grade: moderate
Ferrosilite (mol%): 53.7±3.6
Wollastonite (mol%): 15.1±5.0
Classifier: C. Agee, UNM
Type spec mass (g): 21.9
Type spec location: UNM
Main mass: John Divelbiss
Comments: Field name MAS-4; submitted by C. Agee, UNM
Institutions
and collections UNM: Institute of Meteoritics MSC03 2050 University of New Mexico Albuquerque NM 87131-1126 USA, United States; Website (institutional address; updated 12 Feb 2015)
Catalogs:
References: Published in Meteoritical Bulletin, no. 109, in preparation (2020)
Find references in NASA ADS: NASA ADS
Find references in Google Scholar: Google Scholar
Geography:
Algeria
Coordinates: Unknown.
Statistics:
This is 1 of 1051 approved meteorites from Algeria (plus 26 unapproved names) (plus 4 impact craters)