Northwest Africa 12590 (NWA 12590) Morocco Purchased: 2018 Jun Classification: Carbonaceous chondrite (CV3) History: Several fragments of the same material with total weight of 1805 g were purchased by Sergey Vasiliev from Moroccan meteorite dealer at the St. Marie-aux-Mines mineral show in June 2018. Physical characteristics: Total mass of several pieces is about 1.8 kg. The interior of the meteorite is dark brownish-gray to dark gray whereas surface is dark brown with resinous luster. Petrography: (Pavel Yu. Plechov, FMMR). Petrographic observation of a polished section shows that meteorite composed of chondrules (to 2 mm, average size about 1 mm) set in abundant matrix (about 50 vol%). Large chondrules often have clear pronounced magmatic rims (100-300 µm in width). PO-IA-type prevails among porphyric chondrules. Olivine has relic cores of Fa0.4-9.9 whereas surrounding olivine and olivine in matrix is Fa40-45. Some olivine in PO chondrules contains small rectangular melilite inclusions. Primary magmatic glass is partially crystallized to submicron aggregate. Fluffy CAIs are common and consists of melilite, spinel and Al-diopside. Huge compact CAI in separate polished plate (about 18 mm) has perfect Wark-Lowering rim. Compact CAI consists of spinel, perovskite, grossmanite, Al-diopside, Ti-kushiroite in melilite matrix. No secondary nepheline, sodalite or phyllosilicates were occurred. Tiny drops (up to 2 µm) of hexamolybdenum and other PGE-rich minerals are occurred. Olivine has no undulatory extinction, as well as the absence of opaque shock veins and melt pockets indicates a shock stage of S1. Olivine, pyroxene and metal are absolutely fresh and not weathered (weathering grade W0). Geochemistry: Mineral composition and Geochemistry: EDS-WDS analyses (Pavel Yu. Plechov, FMMR). The primary chondrite assemblage includes olivine in chondrules and matrix Fa 27.51±15.61 (N=59), orthopyroxene Fs2.46±1.52Wo3.02±2.03 (N=15) and partially crystallized glass. Composition of kamacite (in wt.%, N=4): Fe 91.7, Ni 5.65, Co 1.85. Taenite (N=10) contain 38.3 and 0.75 wt.% of Ni and Co respectively. Sulfides are troilite. Compact CAI consists of grossmanite (Fs0.4Wo70.87, Al2O3 = 21.22 wt.%, TiO2 = 14.93 wt., N=11), Ti-kushiroite (Fs0.3Wo68.02, Al2O3 = 19.95wt.%, CaO = 24.35 wt., N=7), Al-diopside (Fs0.59Wo53.57, Al2O3-8.33 wt.%, N=1), spinel with varying contents of FeO (3-23 wt.%, N=15) and perovskite (Ca-27.5, Ti-33.6, N=2) in melilite (gehlenite) matrix. Measured H2O is about 2.01±0.07 and C is 0.65 wt.% (by CNH elemental analyzer). Classification: (Pavel Yu. Plechov, FMMR). Carbonaceous chondrite CV3, reduced sub-group, S1. Reduced subgrop from the composition of sulfides (troilite only), and metal:magnetite ratio. Specimens: Sergey Vasiliev holds main mass. 39 g, thin section and polished plate with large compact CAI, FMMR.