Diogenite
Polymict
Purchased July 2005
no coordinates recorded
A complete fusion-crusted stone weighing 606 g was found in Northwest Africa and purchased by M. Farmer in Erfoud, Morocco. A portion of the meteorite was sent for analysis to Northern Arizona University (T. Bunch and J. Wittke) and was classified as a polymict diogenite. The main mass was subsequently sold to collector S. Turecki, from whom the above specimen was acquired.
The light-colored matrix of NWA 2923 contains abundant clasts composed of orthopyroxenes (83 vol%) and microphenocrysts of olivine basalts (6 vol%), some showing textures consistent with shock melting and recrystallization. Orthopyroxene clasts exhibit a range of colors, from translucent yellow and green to very dark. Minor FeNi-metal, FeS, and diopside are present. A broad range of shock values is found among the clasts, and the meteorite has experienced only slight terrestrial weathering.
Additional details about the polymict diogenite group can be found on the NWA 1239 page. An alternative classification system for the diogenites and dunites based on mineralogical and petrographical features has been proposed by Beck and McSween (2010), and modified by Wittke et al. (2011). The photo of NWA 2923 shown above is a 1.24 g partial slice.
