[NHCOLL-L:1574] Re: fragmenting fossils

[Martin Tillett]

Your fossils probably have iron sulfides in them and the white residue or
powder is from sulfuric acid. Very much like the stuff that grows on car
battery terminals. Once the process starts it is the beginning of the
end. I have delayed the disintegration process by placing the fossils in a
sealed jar with distilled water. Over time the fossils still
disintegrate. I found several beautiful fossilized cones from fir trees
that were replced with marcasite only to watch them crumble into dust. It
seems that once the specimens are removed from sediments and exposed to
air that oxidation takes over and reacts to the iron sulfides. If anyone
knows of a treatment please share. I have communicated with specialists in
the past and no one knew of any way to "cure the sick fossils".
Martin Tillett

On Tue, 23 Apr 2002, Larkin G. Chases wrote:

> Hello, 
> 
> I was wondering if anyone could give me some advise regarding the
> crystallization and fragmentation of fossils. A few of our fossils are
> growing white crystals which results in the specimen crumbling. There is
> also an acidic smell to the specimens. Is there a way to stop this reaction?
> 
> Also, I noticed that rusty-brown dust is appearing on some of the specimens.
> Possibly iron? Is there a way to stop this?
> 
> Thank you, Larkin
> 
> ****************
> Larkin G. Chases
> Museum Assistant
> HSU Natural History Museum
> 1315 G Street, Arcata CA 95521
> Phone: (707)826-4479
>