Hello Martin, As for NWA 725, here are the details as Stan shared them with me:
Recent O-isotopic analysis of a probable paired stone (number pending) by the Open University resolves the material clearly within the winonaite field: "In particular, the D17O value of -0.431 is in reasonable agreement with the mean value of -0.48 for the winonaite-IAB iron-IIICD iron group determined by Clayton and Mayeda (1996)." In addition, when plotted on a diagram comparing the D17O-isotopic value vs. Fa mol% in olivine (Rumble, III et al., 2005), NWA 725 (Fa 6.1; D17O-isotopic value taken from the paired stone [Turecki, 2005; pers. comm.]) and the winonaites NWA 1463 (Fa 7.4; D17O = -0.45‰), NWA 1457 (Fa 5; D17O = -0.40 ±0.03‰), and NWA 1058 (Fa 6.5; D17O = -0.53‰) all plot very close together within the winonaite field. The inference can thus be made that NWA 725 is actually a winonaite, likely paired with the primitive winonaites NWA 1463 and 1058.
David ______________________________________________ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
