Seventeen fragments of this highly unequilibrated chondrite, totaling 565 g, were found in the desert of Oman. Extended searches of the area produced no additional stones. Based on TL sensitivity data, Jiddat al Harasis 026 was assigned to subtype 3.1.
To discriminate among subtypes below type 3.2, it has been shown that the Cr content of ferroan olivine is an excellent indicator of metamorphism (J. Grossman, 2004; Grossman and Brearley 2005). Chromite exsolves from olivine in the incipient stages of metamorphism, initially producing heterogeneous Cr contents, and eventually homogeneously low Cr content of olivine. In a study by Chizmadia and Bendersky (2006), they determined that this sequence progresses from type 3.0, corresponding to high Cr2O3 contents of 0.30.4 wt%, to type 3.2, in which Cr2O3 constitutes less than 0.1 wt%. The gap between these two subtypes represents type 3.1. Analyses of the L chondrite NWA 7731 have established that it has a relatively high Cr2O3 content of 0.43 (±0.11) wt% as well as other features (e.g., igneous zoning of Cr in olivine, sulfur-rich opaques) consistent with a classification of 3.00 (Agee et al, 2013).
Thin section studies have resolved an abundance of large, highly fractured chondrules of types RP, PO, and BO. This meteorite has a shock stage of S3 and is highly weathered to a grade of W3. The specimen of JaH 026 pictured above is a 0.58 g partial end section. In the top photo below are several fragments from this find, while the bottom image is an excellent petrographic thin section micrograph of JaH 026, shown courtesy of Peter Marmet.
Photo courtesy of Comet Meteorite Shop
click on image for a magnified view
Photo courtesy of Peter Marmet