Pyrite in fossils

I have severe problems with fossils from the rheinish-slate
mountains in Germany. The fossils are usually preserved as pyrite
(iron-sulfide) and the specimens I'm working on are in a very bad
condition. Because of high air-humidity the pyrite started to decay
and now there are white crusts on top of the fossils. The crusts can
be easily removed with a sandblasting device using iron powder for
blasting.

After the treatment I want to protect the specimens from further
decay by impregnating them. A German company offers a
"Pyrite-conserve for fossils" based on a Ethanolaminthioglycollat.
Does anybody have any experience with this agent? Or are there
better ways to conserve pyrite?

Michael Maus
Johannes-Gutenberg-University
Institute for Geosciences / Dept. Palaeontology
Becherweg 21
55099 Mainz
Germany


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                  Conservation DistList Instance 15:42
                 Distributed: Friday, December 7, 2001
                       Message Id: cdl-15-42-012
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