NORTHWEST AFRICA

Many possibly paired stones and fragments representing a unique rumurutiite are thought to be distributed in both Europe (300 g stone) and the United States (400 g fragments). The specimen shown above is from a lot of two large, fresh, partially fusion-crusted stones weighing together 2,635 g, which were acquired by American collectors/dealers. A type sample from these stones has been sent to Northern Arizona University for analysis and assignment of a provisional NWA-series number.

This rumurutiite exhibits clasts representing a wide variety of petrologic types: dark-colored clasts containing distinct chondrules are the most highly unequiliberated representing type 3 material, while light-colored clasts are more highly metamorphosed representing petrologic types as high as 6. A modified version of the Van Schmus–Wood classification scheme has been proposed by Berlin and Stöffler (2004) to accommodate the R chondrite metamorphic variation present in the pyroxene, feldspar, and sulfides, especially the lack of low-Ca pyroxene in types 5 and 6:

Modified Van Schmus–Wood Classification Scheme For R Chondrites

	3	4	5	6
Homogeneity of olivine	>5% mean deviation	homogenous	homogenous	homogenous
Pyroxene	predominantly low-Ca pyroxene	low-Ca and Ca-rich pyroxene	only Ca-rich pyroxene	only Ca-rich pyroxene
Feldspar	small glassy intergrowths	isolated intergrowths	networks forming	well-developed networks
Sulfides	even distribution	even distribution	even distribution	mobilized

A more comprehensive look at the rumurutiite chondrite group can be found on the DaG 013 page. The photo shown above is a 1.89 g slice exhibiting a range of petrologic types in this R chondrite breccia.

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