[NHCOLL-L:4141] RE: Cleaning oxidized pyrite mineral specimens

[Moore, Simon]

Hi Robyn,

I always use Rob Waller's method (I think that it was his!) of using
ammonia vapour to neutralise the iron salts and to reduce the size of
the water of crystallisation molecule.  Sorry I don't have the reference
handy but I think it's in Collection Forum c. 1990.

 Closed container with small beakers (100ml) half-filled with PEG-400
(poly-ethylene glycol), then add about 3ml of 0.880 ammonium hydroxide,
leave overnight.  Not used ETG as yet nor heard of Super Iron Out....?

Hope that this helps but I'm sure you'll have plenty of replies!

With all good wishes, 
Simon Moore, MIScT, FLS, ACR,
Senior Conservator of Natural Sciences. 
Hampshire County Council
Recreation & Heritage Department,
Museums & Archives Service,
Chilcomb House, Chilcomb Lane,
Winchester SO23 8RD. UK.
Internal  8 327 6737
01962 826737
http://www.hants.gov.uk/museum/biology 



-----Original Message-----
From: owner-nhcoll-l at lists.yale.edu
[mailto:owner-nhcoll-l at lists.yale.edu] On Behalf Of Robyn Hodgkins
Sent: 09 January 2009 00:54
To: NHCOLL-L at lists.yale.edu
Subject: [NHCOLL-L:4140] Cleaning oxidized pyrite mineral specimens

I am a UCLA chemistry graduate student helping the Natural History
Museum of Los Angeles County Mineral Science department. They have
several minerals containing iron sulfides that have become brown in
color. The corrosion has not been completely identified, but we believe
it is mainly oxidized pyrite corrosion. The Museum is interested in
cleaning these minerals. I have found literature about using
ethanolamine thioglycollate to clean. Has anyone used this or has an
opinion of how this would compare to Super Iron Out? thanks!

Robyn Hodgkins
Graduate Student
Garrell Group
UCLA Chemistry and Biochemistry
hodgkins at chem.ucla.edu
310-206-9434


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