[meteorite-list] Admire Pallasite Destruction!
From: Matt Morgan <mail_at_meteoritecentral.com>
Date: Mon, 19 Nov 2012 10:01:04 -0700
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.
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.
Mile High Meteorites
P.O. Box 151293
Lakewood, Colorado 80215
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Received on Mon 19 Nov 2012 12:01:04 PM PST