[meteorite-list] Admire Pallasite Destruction!
From: Matt Morgan <mail_at_meteoritecentral.com>
Date: Mon, 19 Nov 2012 10:01:04 -0700 Message-ID: <ac9687de-4a2c-4bf7-8d2c-7524f5dc13ca_at_email.android.com> A general but related question...how long is a dealer to be held "responsible" for the specimen? I've had customers come back after 10 years and want a refund for a rusty Imilac. Typically, I work something out but I don't think a lifetime guarantee is warranted. Opinions? Matt MikeG <meteoritemike at gmail.com> wrote: >Hi Don and Adam, > >I am not nearly as experienced as either of you. Having said that, I >have seen and owned stable specimens of Brenham and Admire. I will >not argue against the ruster reputation, because there are numerous >examples of these pallasites self-destructing. > >The problem is, mainly, the preparation. If you cut a meteorite using >tap water or anything other than distilled water, you are guaranteeing >that specimen will be unstable. You might as well smash it with a >sledgehammer and throw it in the garbage can. Why people try to cut >corners and save money by refusing to purchase distilled water is >beyond me. Any water that is not distilled will contaminate the >specimen - every time, without exception, pallasite or not. It's the >lazy man's way to cut. The only excuse is if the cutter is using a >giant 16" slab saw (or big wire saw) that requires a constant flow of >many gallons of coolant - and distilled water would not feasible. > >Second part of preparation problem is proper handling during and after >cutting - have a hot oven waiting at 250F and immediately put the >freshly-cut specimen into the oven for 12-16 hours to purge remnant >moisture from cutting. Skipping this step is suicide for a specimen, >especially for irons and stony-irons. > >After cutting and drying, put the specimen into a climate-controlled >container with dessicant. > >When prepared like this, any specimen (including rusters) will be much >more stable and last much longer. I've sold specimens of Brenham to >customers years ago, and they still have them, intact and rust-free in >their collections. No complaints. > >I think we also cannot overlook the initial found state of the >specimen - some are inherently more stable than others because of the >conditions they endured before being recovered. > >Lastly, there are intensive methods to purge contaminants and >stabilize a sick specimen - whether it's regular old rust or something >more insidious like Lawrencite disease. Different methods are out >there and they vary in effectiveness, but some do work. > >Personally, I avoid specimens that have reputations of rusters, but I >do not write them off entirely. I go on a case by case basis - >depending on the seller and how it was prepared. Now, if I lost >thousands of dollars on a big unstable specimen of something like >Brenham (like Adam did), it would likely sour me to all of them >entirely. So Adam's position is understandable. I just don't agree >that all Brenhams are unstable rusters that will disintegrate over >time. From my own collection, I had a ~30g thin slice of etched >Brenham that I purchases from Robert Ward on eBay years ago. It was >superb and rust-free. I had it on display in humid Florida for two >years before reselling it. Last time I talked to the buyer, it was >still rust-free - about 5 years after purchasing it. > >My advice is - if you want to take a chance on a ruster, ask a lot of >questions regarding the preparation first. > >Best regards, > >MikeG ________________ Matt Morgan Mile High Meteorites P.O. Box 151293 Lakewood, Colorado 80215 USA http://www.mhmeteorites.com Like Us on Facebook: www.facebook.com/MileHighMeteorites Received on Mon 19 Nov 2012 12:01:04 PM PST |
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