FMF - Friends of Minerals Forum, discussion and message board

[vic rzonca]

I bought this Muscovite in Tucson this year. Upon an olfactory inspection after unwrapping it at home, I detect a strong odor of an oil-wax compound. This is the second time I've found this condition on a specimen from Brazil and I know its a common treatment, but I'd like to clean it off. It does not smell like common mineral oil and I wonder about the compounds that might be used. I know that waste oil can be a hazard and I've heard of this extreme example, poly-chlorinated-bi-phenol transformer oil being sprayed on roads as dust control years ago in the US. A soak in acetone, in a closed container for X amount of days, outside, would probably do the trick. But, I still wonder about these compounds. Thanks.

[Jesse Fisher]

Given all the possibilities, it's almost impossible what sort of oil the specimen may have been treated with. If it has an odor then likely something other than mineral oil or silicone spray was used. A while back I came across a fluorite that had been treated with what I think is a floor wax, which had a distinctive odor.

Unfortunately, anything "waxy" will probably not dissolve in acetone, though it is always good to give it a try and see what happens. If the acetone doesn't do the job they you will likely need a stronger organic solvent such as MEK. While acetone is relatively benign, some other solvents are not so. Always use these things with chemical-resistant gloves and in a well-ventilated place. And, of course, use glass containers for soaking, not plastic.

[vic rzonca]

Methyl-ethyl-keytone. Terrible stuff. Learned to hate it in the plate engraving shop. Glass container for sure. Right you are. Thanks Jesse.

[Jesse Fisher]

yes, it does have a lovely aroma!

[Martin Rich]

Try brake cleaner!

Martin

[vic rzonca]

That is a good idea, Martin, highly solvent and in an easy to use, spray form. Maybe a bit more pricey per drop, but a brilliant thought. You must spend time under the bonnet. Thanks.