Hello Pete: Off the top of my head -- I don't recall ever hearing of "indigo" blue in a meteorite. I do know that ringwoodite is barely translucent with a pale purple-over-brown tint especially visible to the eye under a low power loupe. Perhaps it is just semantics.
When the list last visited ringwoodite veins, I believe they were almost always found in L chondrites but this could have been from paired finds. I say this suggesting that the bulk of ringwoodite veins observed/sampled on earth might have come from the same disrupted parent body-- but have nothing other than vignette evidence to support it. I believe your discovery is about right regarding ringwoodite abundance. I have seen swellings of ringwoodite veins to about 3-5mm but 1mm is normal. Ringwoodite veins are likely injection veins along existing fractures/lines of weakness. The purity of the veins does not suggest the veins occur as flash melts. About 8 years ago there was a run of ringwoodite bearing slices being sold but I believe it came from a larger find of multiple stones--Sorry I don't have the NWA numbers. Please send a photo when /if you can. Elton --- On Wed, 1/21/09, Pete Pete <[email protected]> wrote: > From: Pete Pete <[email protected]> > Subject: [meteorite-list] Ringwoodite > To: "meteoritelist meteoritelist" <[email protected]> > Date: Wednesday, January 21, 2009, 6:12 PM > Greetings, all, > > > In the experience of the chondrite-cutters, how common are > you finding ringwoodite in shock melt veins? > > Personally, I've only seen (what I believe to be) > ringwoodite in two stones out of the dozens I've cut. > > How about size? In mine, the largest area is ~ .5 mm. > > For such an outstanding indigo blue colour in a generally > brown matrix, I'm surprised there isn't that much > information about the mineral in meteorites on the internet > or my books. > > Cheers, > Pete > ______________________________________________ http://www.meteoritecentral.com Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
