[meteorite-list] Mohr's value for stoney meteorites

From: MexicoDoug_at_aol.com <MexicoDoug_at_meteoritecentral.com>
Date: Sat Jun 24 05:00:42 2006
Message-ID: <514.1760122.31ce5935_at_aol.com>

Walter N. wrote:
>>I guess the best way to find out is just go ahead and do it.
ONE THOUGHT - Why distilled water? I always use tap.<<
 
Hola there again, The "Just do it" jingle has a lot going for it in this
field. After you just do it...please just tell it!
 
I have a nice 8" saw (which is why the blade prices I quoted were a bit high
- sorry). The distilled water is basically for the same reason you want to
put distilled water in your car's radiator, never tap. People do it of
course but then the steely insides of their circulatory system begin to corrode
and make this ugly brown gunk (meteorite cyanide) and car gets a case of what
meteorite people know better informally as Lawrencite Disease, which you can
read about attacking iron meteorites in O. Richard Norton's classic book
(Illustrated by his talented wife, Dorothy), "Rocks from Space".
 
While the stony meteorites don't have symptoms immediately as bad as the
irons, like concrete, they do absorbe a lot of water. You can experiment to
find out how much with a cut open meteorite, a precision scale and an oven.
It'll take about three hours at 160 170 degrees F to start talking turkey w/r to
drying them. Tap water any some other forms of chlorinated water releases
halide ions and as an atom is possibly involved in the catalytic oxidation of
iron. A stony which is not to far weathered (i.e., has a good quantity of
its reduced iron flecks intact, among other measures) like a sponge will get
impregnated with the suspected bad stuff mentioned and eventually your
beautiful slice which had white steely reflections will develop amber brown measles
in there place. It can be repolished as many undoubtably are sadly on eBay,
but it won't last shiny forever for you can suspect why.
 
Using tap water is a classic case of irresponsibility in meteoritics though
undoubtably someone out there in my cyberzoological garden will defend it.
(May they come forth so I put them on my piddly black list of suppliers).
Multiple alcohol soaks is way to go for highest drying efficiency and
contaminant removal. Once should be fine iuf you use distilled H20 and maybe
unnecessary in that case. But if you use anything besides pure alcohol or distilled
water then you really should be doing alcohol soaks. Each saok can remove a
heafty % of the corrosives. While you do it, you can try to comfort yourself
with the knowledge that meteorites are special compared to 99.999995% of the
rest of the Earth rocks due to their containing reduced iron that is
vulnerable to rusting (and chlorine also is the trick to dumping corrosive table salt
in the water since ther are alway sodium ions in these cocktails looking for
partners.) A beautiful geode or agate doesn't mind tap water because it is
quite stable. This is a case of one rock's cosmetic bath is another rock's
poison.
 
Hope that clears it up more than mud. Please read up on it, I am sure I
missed a few good thoughts on this and interpreted a couple of things too
conservatively, but that's how I look at the world,
 
Saludos, Doug (best oven temp is about 160 deg F for an hour min. You may
"just" be dealing with NWA's but the pride you'll probably have in your
product will probably be woth the inconvenience many times over, not to mention in
helping you develop good technique for more financially challenging
meteorite situations. But some people use IR heat lamps (available at home depot and
using less power) with alledgedly superb results...(PS another expert out
there signs messages JWG. I am not sure if he can add to this on blades, but
as you experiment more he is also nice oracle to have up your sleeve and
kindly shares info.)
Received on Sat 24 Jun 2006 05:00:37 AM PDT


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