ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
|
Post by ericabelle on Nov 12, 2022 8:44:16 GMT -5
I have a newly-acquired pyrite sun dollar and am needing advice about how to clean it (or even if I should try.) And I've read that some forms of pyrite are likely to degrade. I've been reading that something called "Pyrite Stop" is great for protecting pyrite, but it looks like it is just sold in the UK. Has anyone had success protecting pyrite with another method? Here's some photos if you'd like a look   |
|
ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
|
Post by ericabelle on Nov 14, 2022 19:32:38 GMT -5
So, since no one has any ideas yet, I'm thinking of either encasing it in epoxy resin or launching it into outer space......epoxy resin probably gonna be cheaper, tho
|
|
|
|
Post by hummingbirdstones2 on Nov 15, 2022 8:52:33 GMT -5
There are outdoor polyurethanes that don't yellow like indoor ones. Spraying a couple of light coats of that - to avoid pools and runs - might let you retain more of the texture of your specimens. I sprayed a faced septarian chunk for a friend's wife several years ago and it hadn't yellowed last time I saw it.
Maybe now someone else will provide a better method. I've never liked urethane as a matter of principle, but you can clean and recoat it if needed.
|
|
|
|
Post by rmf on Nov 15, 2022 13:12:22 GMT -5
the problem with pyrite suns is that they are not all pyrite. They are usually composed of pyrite and marcasite.
The orthorhombic form of iron disulfide, FeS2, is called marcasite, while pyrite is isometric form of iron disulfide, FeS2. Marcasites crystal structure is less stable than pyrite and decomposes much easier. Be sure to keep it dry. Once it starts to decompose it is hard to stop. heating in the oven or under a lamp to make sure any surface moisture is gone before sealing. Clear varnishes will work as will cyano-acrylic glue (CA).
|
|
ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
|
Post by ericabelle on Nov 15, 2022 19:46:04 GMT -5
the problem with pyrite suns is that they are not all pyrite. They are usually composed of pyrite and marcasite. The orthorhombic form of iron disulfide, FeS2, is called marcasite, while pyrite is isometric form of iron disulfide, FeS2. Marcasites crystal structure is less stable than pyrite and decomposes much easier. Be sure to keep it dry. Once it starts to decompose it is hard to stop. heating in the oven or under a lamp to make sure any surface moisture is gone before sealing. Clear varnishes will work as will cyano-acrylic glue (CA). Thanks so much! |
|
QuailRiver
fully equipped rock polisher
Member since May 2008
Posts: 1,640
|
Post by QuailRiver on Nov 16, 2022 11:58:20 GMT -5
Some in the furniture industry use water clear butyrate lacquer to spray and protect brass hardware from tarnishing, and on other metals to keep them looking bright. Might work on pyrite too but I haven't tried it for that. Butyrate lacquer is available in aerosol cans and in different sheens. I used to buy it from Mohawk Finishing Products. And I think Sherwin Williams used to sell it and maybe still does in aerosol form. Also there was a another company called ML Campbell that made a modified acrylic lacquer that would adhere well to metal surfaces and dried to a hard coating that was very good. But the ML Campbell stuff was slightly amber in color and the smallest quantity their dealers would sell was one gallon. Edited: After posting the above I started thinking about how a lot of the finishes and solvents that I used to use with furniture have had to be reformulated in the last few years due to newer government regulations. So I decided to look on Mohawks's site and found that they now sell an aerosol formula that is said to be for brass and other brass plated metal surfaces. Available in gloss, matte and satin sheens. Although pyrite isn't brass, as long as there isn't a weird chemical reaction to the iron or another element in pyrite then it would probably work. But I would suggest testing it on a much lesser piece than that fine looking pyrite coated sand dollar fossil you're showing in your OP. www.mohawk-finishing.com/products/wood-staining-finishing/industrial-coatings/lacquer-for-brass/ |
|
ericabelle
spending too much on rocks
Instagram acct: @erica_shoots_everything
Member since April 2021
Posts: 482
|
Post by ericabelle on Nov 16, 2022 20:14:31 GMT -5
Some in the furniture industry use water clear butyrate lacquer to spray and protect brass hardware from tarnishing, and on other metals to keep them looking bright. Might work on pyrite too but I haven't tried it for that. Butyrate lacquer is available in aerosol cans and in different sheens. I used to buy it from Mohawk Finishing Products. And I think Sherwin Williams used to sell it and maybe still does in aerosol form. Also there was a another company called ML Campbell that made a modified acrylic lacquer that would adhere well to metal surfaces and dried to a hard coating that was very good. But the ML Campbell stuff was slightly amber in color and the smallest quantity their dealers would sell was one gallon. Edited: After posting the above I started thinking about how a lot of the finishes and solvents that I used to use with furniture have had to be reformulated in the last few years due to newer government regulations. So I decided to look on Mohawks's site and found that they now sell an aerosol formula that is said to be for brass and other brass plated metal surfaces. Available in gloss, matte and satin sheens. Although pyrite isn't brass, as long as there isn't a weird chemical reaction to the iron or another element in pyrite then it would probably work. But I would suggest testing it on a much lesser piece than that fine looking pyrite coated sand dollar fossil you're showing in your OP. www.mohawk-finishing.com/products/wood-staining-finishing/industrial-coatings/lacquer-for-brass/Thank you! I'll definitely look into those probducts - sounds like they would be airtight finishes |
|
