{"product_id":"bir-ounane-001-primitive-achondrite-meteorite-end-cut-achondrite-prim-70-22g-mirror-polished-face","title":"Bir Ounane 001 Primitive Achondrite Meteorite End Cut, Achondrite-prim, 70.22g, Mirror Polished Face","description":"\u003ch2\u003eBir Ounane 001, a 70.22 gram polished end cut\u003c\/h2\u003e\n\u003cp\u003eThis end cut of Bir Ounane 001 keeps one natural exterior surface and exposes a mirror polished interior face of 70.22 g. The Meteoritical Bulletin classifies Bir Ounane 001 as a primitive achondrite (Achondrite-prim), a meteorite that was heated and recrystallized on its parent body without fully separating into a core and a crust. Its writeup calls it an olivine websterite, and its mineral chemistry does not match any established group.\u003c\/p\u003e\n\u003cp\u003eOne of 16 approved meteorites classified as Achondrite-prim, as recorded in the Meteoritical Bulletin database in September 2026. That is a count of database entries rather than separate falls: the Bulletin entry for Northwest Africa 15061 records it as likely paired with Bir Ounane 001.\u003c\/p\u003e\n\u003ch2\u003eSurface and features\u003c\/h2\u003e\n\u003cp\u003eThe cut face is polished to a mirror finish and has not been coated or sealed. Against the gray groundmass the metal reads as bright silver flecks scattered across the whole face, with fine pale veinlets running between them. The Bulletin describes numerous oxidized crosscutting veinlets throughout the meteorite, and those are what the veining on this face shows. A natural break runs across the lower part of the face, and the back and sides keep the weathered brown exterior of the stone.\u003c\/p\u003e\n\u003cp\u003eUnder close light the polish holds a clean reflection, so the granoblastic texture described in the Bulletin can be read directly: tightly interlocking silicate grains, most of them under half a millimeter, rather than the round chondrules of a chondrite.\u003c\/p\u003e\n\u003ch2\u003eDiscovery and provenance\u003c\/h2\u003e\n\u003cp\u003eAccording to the Meteoritical Bulletin, Bir Ounane 001 was found in 2022 by Sahrawi meteorite hunters roughly 118 km southeast of Taoudenni in the Gao region of Mali, with the locality of Bir Ounane about 84 km southwest of the find site. Multiple identical appearing stones were recovered, totalling 80 kg, the largest weighing 9,883 g.\u003c\/p\u003e\n\u003cp\u003eThe meteorite was classified by A. Ross and C. Agee at the University of New Mexico, with oxygen isotope analysis by K. Ziegler at the same institution. It was approved on 11 December 2022 and published in Meteoritical Bulletin 111 (2023). The Bulletin records 109.3 g on deposit at UNM and the main mass with Bachir Salek. This end cut was acquired by Treasure Coast Meteorite Co.\u003c\/p\u003e\n\u003ch2\u003eScientific context\u003c\/h2\u003e\n\u003cp\u003ePrimitive achondrites sit between the chondrites and the fully differentiated achondrites. Their parent bodies were heated enough to recrystallize and begin melting, but not enough to separate metal from rock completely, so they keep a composition close to their chondritic starting material while losing the chondrules that would identify them as chondrites.\u003c\/p\u003e\n\u003cp\u003eThe Bulletin records Bir Ounane 001 as an olivine websterite made of forsterite (30 to 40 percent), enstatite (40 to 50 percent), diopside (10 to 20 percent) and andesine plagioclase (5 to 10 percent), with kamacite and oxidized iron at 5 to 10 percent and minor troilite, daubreelite and schreibersite.\u003c\/p\u003e\n\u003cp\u003eIts classification is a puzzle worth stating plainly, because the Bulletin itself sets it out. The magnesian silicates and the daubreelite resemble winonaites. The metal abundance resembles acapulcoites and lodranites. The fine grain size fits winonaites or acapulcoites but not lodranites. The oxygen isotope value Delta-17O is consistent with acapulcoites and lodranites, while its delta-18O is higher than the usual range for those groups, and the triple oxygen isotope values are unlike winonaites. No established group accounts for all of it, which is why the Bulletin classifies it as a primitive achondrite not belonging to a known group. More on how these classifications are decided is set out in \u003ca href=\"\/pages\/meteoritical-bulletin-explained\"\u003eunderstanding the Meteoritical Bulletin\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch2\u003eFrequently asked questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWhat is a primitive achondrite?\u003c\/strong\u003e A meteorite whose parent body was heated and recrystallized, and began to melt, without separating fully into layers. It keeps a near-chondritic composition but has lost its chondrules.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhy is it called ungrouped?\u003c\/strong\u003e Its mineralogy and oxygen isotopes do not match any established group. The Bulletin classifies it as a primitive achondrite not belonging to a known group, and its writeup compares it with winonaites, acapulcoites and lodranites without placing it in any of them.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHas the face been coated or treated?\u003c\/strong\u003e No. The polished face is bare metal and silicate, with no coating, sealant or wax.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow many meteorites like this are known?\u003c\/strong\u003e The Meteoritical Bulletin database lists 16 approved Achondrite-prim entries as of September 2026. Pairing matters here: the entry for Northwest Africa 15061 records it as likely paired with Bir Ounane 001, so the number of separate falls is smaller than the entry count.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHow do I know it is what it says?\u003c\/strong\u003e The classification can be checked directly in the \u003ca href=\"https:\/\/www.lpi.usra.edu\/meteor\/metbull.cfm?code=78564\" rel=\"noopener\" target=\"_blank\"\u003eMeteoritical Bulletin Database entry for Bir Ounane 001\u003c\/a\u003e. Treasure Coast Meteorite Co. is IMCA Member #3323.\u003c\/p\u003e\n\u003ch2\u003eCollector significance\u003c\/h2\u003e\n\u003cp\u003eAn end cut gives both halves of the story in one piece: the weathered exterior the stone arrived with, and a polished interior face showing the texture and metal that classification is based on. At 70.22 g this is a substantial piece of a meteorite with no group of its own, from a total recorded mass of 80 kg. Browse more in the \u003ca href=\"\/collections\/primitive-achondrites\"\u003eprimitive achondrite collection\u003c\/a\u003e, or see the \u003ca href=\"\/collections\/ungrouped-achondrites\"\u003eungrouped achondrites\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eClassification data from the \u003ca href=\"https:\/\/www.lpi.usra.edu\/meteor\/metbull.cfm?code=78564\" rel=\"noopener\" target=\"_blank\"\u003eMeteoritical Bulletin entry for Bir Ounane 001\u003c\/a\u003e. Treasure Coast Meteorite Co., IMCA Member #3323.\u003c\/p\u003e","brand":"Treasure Coast Meteorite Co.","offers":[{"title":"Default Title","offer_id":46238295621679,"sku":"BIR-OUNANE-001-70.22G-ENDCUT","price":560.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0726\/9724\/9839\/files\/bir-ounane-001-70.22g-01-polished-face.jpg?v=1790104219","url":"https:\/\/www.tcmeteorites.com\/products\/bir-ounane-001-primitive-achondrite-meteorite-end-cut-achondrite-prim-70-22g-mirror-polished-face","provider":"Treasure Coast Meteorite Co.","version":"1.0","type":"link"}