[meteorite-list] Record Nevada Chondrite Find

From: countdeiro at earthlink.net <countdeiro_at_meteoritecentral.com>
Date: Sun, 7 Mar 2010 14:46:59 -0500 (EST)
Message-ID: <16872631.1267991220043.JavaMail.root_at_wamui-hunyo.atl.sa.earthlink.net>

 Hello List,
Several Listees overseas, and here in the States, have asked me for details on the handling of the record 12.7kg chondrite I stumbled over in the Nevada desert last Wednesday, Mar.3rd. while on a hunt with my friend and neighbor in Las Vegas, Sonny Clary and his dog, Brix.
Sonny and I have already taken the specimen to Adam Hupe' in Laughlin, Nevada and had it cut in half. Adam is an expert meteoriticist and had the only diamond blade large enough to cut the rock.(24") It was barely large enough to slice the rock. Yes, this was a difficult decision to make. I had agreed to share with Sonny the other piece and kept the choice piece for myself. We have an agreement that what we find ..we share equally if possible. We took many photos before and during the cutting to document the find and it's provenance.
The meteorite was badly fractured from it's descent and weathering in the desert and we spent several hours stabilizing the large cracks in it with Paleo Bond before we dared subject it to the saw. We had great difficulty blocking and securing the meteorite for cutting. At slow speed on the saw, it took almost an hour as we watched nervously. Adam did not want to stress the specimen. he did an excellent job. No saw marks. Precision equipment. We were lucky that only a few fragments fell out and we repaired those.
Sonny and I are now polishing the respective cut faces. The meteorite appears to be a metal poor chondrite.
After the cut and on cursory first inspection, I saw many good sized chondrules 1mm to 4mm and localized scatterings of small blebs of metal 1mm+. Adam mentioned that the interior looks remarkably fresh. I will have to wait till I finish polishing to see any remarkable clasts, or inclusions. Adam guesses that it will come back as an L4/5 chondrite. At 12.7kg, it is by far the largest intact chondrite recovered in Nevada...my home state. Gross measurements before the cut were 250mm high by 180mm wide by 120mm deep.
My half mounts vertically, as it was found, with the oriented face having several nice thumb sized regs and protruberances. The other natural sides indicate that perhaps larger pieces broke off during descent (slickenslides?).
As to preparation for display, I will make sure the cracks are completely sealed and then remove the excess Paleo Bond with acetone followed by a gentle brushing with a hand held stainless steel Dremel to remove only the terrestrial accumulations. There appears to be some small areas of primary and secondary fusion crust on this forward facing side. It is hard to tell the difference, except under magnification, from the desert patination.
What is attractive about this half is that the peak of the rock is prominent and the line of demarcation from what was buried shows how little of the meteorite was protruding out of the regolith.... like a small shark fin, or iceberg.

I welcome any comments as to my decision on how to handle this record find...my first meteorite. To see the find go to Nevada Meteorites.com. Click on Hunts...scroll down.

Count Deiro
IMCA 3536
Received on Sun 07 Mar 2010 02:46:59 PM PST