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GeneralHow to clean rusted/tarnished Pyritized Ammonites?

12th Oct 2019 04:07 UTCDessy Atwell

I purchased a lot of 100 small Pyritized Ammonites from Russia recently! When I got them they were covered in a black residue. I could see underneath that they were nice and shiny. So I said hey, let me just rinse them off. Bad idea. The next morning, some had began to tarnish and turned a blackish color and we're no longer shiny. Fast forward a week later and some are rusted and most are tarnished... 

My question is, how can I safely cleaned the rust off and remove the tarnish? I know the process for Seymchan metiorites, so I'm wondering if it's similar. I'm aware that Pyritized fossils and pyrite tarnish over time. Didn't realize rinsing them with water would do that almost immediately. I found info in the forums on how to preserve them, but not how to clean them after they have tarnished. I'd love to hear your advice! 

12th Oct 2019 05:22 UTCThomas Lühr Expert


Soak them in "Wallers Solution" (google it) or, if you live in the U.S., in "Iron Out" for a day or two. Use a jar with an airtight lid to keep out the oxygen. Repeat it a few times with fresh solution. Then give them a rinse and let them dry fast, but do not heat them.
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