[Nhcoll-l] [External] Iron based meteorites / ferrous material conservation

[Tacker, Christopher]

Kate - depending on age of the meteorite, heaven knows what treatments the meteorite has had. Boiling in oil, in parafin, anything up to animal sacrifice to old gods.

Here's how I would approach it. My apologies if you're already well on your way.

If it were my problem, I'd first hit the Meteoritical Society database. What are you dealing with? It's possible other collections have that specimen. What minor minerals are present? Some of these, troilite, phosphides, are very hygroscopic. These can accelerate oxidation of the specimen. Frank Howe's book is a good, but dated, reference.

Next poll the collection managers that have this sample. What problems do they have with it?

This is essential background. It should provide lots of entertainment, especially if you don't have a background in mineralogy. Contact me off list if that's a problem for you.

These steps will help you develop the long term plan for storage *before* you remove it from oil.

Next, ID the oil. What you need is infrared spectroscopy with Attenuated Total Reflectance, FTIR-ATR. This is literally 10 minutes of work. A drop of oil goes on a diamond. This is a workhorse in Chemistry Departments, or maybe even in your program.
Usually they have a library to help match spectra for ID.

R. Chris Tacker, Ph.D., P.G.
Curator of Geology
N.C. Museum of Natural Sciences
11 West Jones Street
Raleigh, NC 27601

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My name is Kate Lambert and I am currently completing my MA minor thesis at the Grimwade Centre for Cultural Materials Conservation at the University of Melbourne.


My research is on an iron-based meteorite specimen which is currently enclosed in a glass case, submerged in an oil-like substance which is now very discoloured. We think it may be silicone oil, but are unable to run tests due to COVID. Does anyone know of any conservation literature on submerging ferrous materials in oil to retard corrosion? Or has anyone had experience with similarly submerged specimens? Have you attempted to remove the oil and if so was there a particular solvent you used? Or would you recommend just replacing the discoloured oil with the same oil?


Thanks


Kate

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