Description
On offer: a 19.45g individual.
Dimensions: ~29 x 27 mm
What you get: this 19.45g individual, a membrane box, a label and signed Certificate of Authenticity.
Type: Polymict eucrite
Country: Sahara
Date of find: 2013
Total mass: 1612 g
Northwest Africa 8036 (NWA 8036)
(Northwest Africa)
Purchased: 2013 Aug
Classification: HED achondrite (Eucrite, polymict)
History: Purchased by GHupé in August 2013 from a dealer in Erfoud, Morocco.
Physical characteristics: A group of 21 similar stones (total weight 1612 g) exhibiting weathered exterior surfaces and interiors characterized by separated white clasts with some brown staining in a dark matrix. GHupé has cut every stone and carefully examined their interiors as well as exteriors; together with A. Irving it was concluded they were the same material (and the same as the type specimen)
Petrography: (A. Irving and S. Kuehner, UWS) Fragmental breccia composed of small gabbroic eucrite clasts and matrix of related debris, with rare clasts of diogenitic orthopyroxene. Primary minerals are exsolved pigeonite (with variable red-brown staining), calcic plagioclase (polycrystalline, birefringent), silica polymorph, ilmenite, Ti-bearing chromite and troilite; secondary barite and calcite are present.
Geochemistry: Orthopyroxene host (Fs58.2Wo3.9, FeO/MnO =30), clinopyroxene exsolution lamella (Fs28.4Wo41.4, FeO/MnO = 30), diogenitic orthopyroxene (Fs17.0Wo1.1, FeO/MnO =29; Fs35.4Wo1.2, FeO/MnO = 38).
Classification: Eucrite (polymict, gabbroic). Based on primary textures, shock features and style of weathering, these stones are likely paired with NWA 7989.
Specimens: A total of 25.2 g including one polished thin section at UWB. The remaining material is held by GHupé.
