[meteorite-list] Patina

[Gary K. Foote]

Thanks Doug, for your thoughtful analysis.  I had a piece of campo with an unusual shape 
that came to me rusty and not looking like it was going to stop rusting.  I took a wire 
brush to it and removed the rust and now have a specimen that still shows flight details 
and has nearly no rust.  The only drawback is that I had to expose the high spots right 
down to shiny metal to get the rust out of the low spots.  I'm sure I lost some material, 
but think it was minimal.  

I've seen pallasites chopped up into medallions and such on ebay and think that kind of 
manipulation is over the line, but I believe that what I have done makes the specimen 
more 'enjoyable' to view.  If you would like to see pics of before and after the links 
are below;

Before:  http://www.meteorite-dealers.com/images/campo-the-hand-600.jpg

After:   http://www.meteorite-dealers.com/images/campohand-wirebrushed.jpg

Gary

On 12 May 2006 at 9:47, MexicoDoug at aol.com wrote:

> Gary F. writes:
> 
> <<Which is best value wise?  Original condition with dirt and natural patina 
> or cleaned 
>  with patina left or cleaned and polished free of patina?>>
> 
> Gary,
> Patina...if patina is an arrested natural finish, sounds awesome to me.
> 
> There is "cleaned", and then there is "cleaned" just as there are stones and 
> there are irons, and "scientific value" and "sentimental value" and "trade-in 
> value".  Never clean stones with solvents.  Distilled water and reagent grade 
> alcohol are in a questionable category here and questionable equates to not 
> necessary.  If the dirt comes off with your hands (and not a wire brush by 
> wearing down the surface of the stone or iron, of course it is recommendable to not 
> have such dirty meteorites in your collection - they will make everything 
> dirty wherever you put them.)  The one exception to the solvent rule is the 
> ultimate form of cleaning - hacking off slices.  To make a cut, you will need a 
> friendly solvent - but you aren't asking about cutting.
> 
> If you have a stable iron, the same applies.  In economics there is a value 
> to an option.  Give the next guy a chance with the option "to clean or not to 
> clean, and that is the question".  If you choose to clean it, you will 
> eliminate some of the demand because you have killed that option for those who want a
> natural meteorite.  Less demand = less value both scientifically and one would expect
> monetarily.  Same goes for whether you should cut a nice looking whole individual - don't.
> 
> If you don't have a stable iron, you don't have much choice in the matter.  
> Either you find an acceptable way to clean it or you will be left with a pile 
> of junk.  Pile of junk futures are not very scientifically or commercially 
> valuable, though in this field there are suckers born every minute to keep such 
> futures alive.  The iron is rented anyway as it is a matter of time... So brush 
> it with a stainless brush, boil it in parrafin, strip it, coat it in PU, 
> pickle it a bit and then saponify it in caustic soda, vacuum pack it in beef jerky 
> factory, sell it on ebay, whatever your heart enjoys.  Have as much fun as I 
> do when you are handed a sledgehammer at a carnival to smash a useless car, or 
> as a shifty used car dealer who fixes up an old jalopy enough to have his 
> hapless* customer drive it out the door...If it is a rare iron, though, better yet 
> leave it alone and trade or give it to a museum so they can evaluate how to 
> best preserve it for humanity, unless you realistically believe you can do a 
> better job or have Bill Mason on your staff.
> 
> *cool word, borrowed from a recent post
> 
> Hope this helps.  As you can see I am of the strict don't clean anything 
> unless it is absolutely necessary belief.  But then you have the irons that are 
> borderline.  For them, you want the natural naughty Squirrel Nutkin finish-and 
> not sandblasted down to the patina and beyond- if an arrested natural nutshell 
> exists.  But if it doesn't (because one didn't develop, or because the soil 
> was part of it and now the soil is removed), a good wire brushing may be in 
> order though you will lose some weight, you will minimize the surface area for 
> absorption of water and buildup of other catalytic corrosives...
> 
> Saludos