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steveshq
Hello all, its been a while since posting.  Been hiding under a big rock (with a bone in!) lol.

Anyways... I done a great cut on my diamond wet cutter through a solid pyrite nodule that showed a small edge of an ammo.  Took much deliberation using my inbuilt X-Ray vision and a pencil to decide where to cut... Got it bang on!

You can see different coloured crystals filling a golden ammo and complete right down to the tiny centre, I was so lucky...

Although the cut was a good one, I now need to polish it up a bit to show it off a bit more.

So, do you treat a stable dark green Pyrite smooth nodule as if it was a regular rock / Stone when it comes to polishing?  I mean same procedures like type of sanding disks used and polishes?

Never attempted polishing Pyrite and wondered that even if successful, will it tarnish like Silver does?

Cheers Guys 

[thumb] sorry, scale is 4 inches across.



my pyrite cut ammo from Port Mulgrave.jpg 
"A moment of the past will only live as long as the last person who remembers it"
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prep01
Hello Steve, the short answer is YES! Just remember that as you've cut it right to the middle, especially on the coarser grits you will be taking off more of the ammonite (It's always best to cut slightly further away from the centre then you can grind down) Good luck - it should look really good!
Colin Huller
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Anonymous
Thanks for the response Colin,
yes I see what you mean about cutting a tad before the target depth as the polishing will remove another half a mil or just less to get rid of those cut lines.

Have you polished anything in Pyrite at all? and does it suffer with tarnishing?

Thanks again [thumb]
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prep01
yes then no (doesn't usually) but you never know what Mother Nature had in store!
Colin Huller
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Anonymous

I have polished quite a few pyrite ammonites and yes, they tarnish very quickly after polishing, although they look beautiful for a while. 

 

You need to be aware of pyrite rot if you are not already. I found one of my specimens in the form of dust and had to rescue all of the adjoining ones. Paraloid B72 and acetone was my chosen preservation method. 

 

 

 

 

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prep01
Hi Anonymous, was it the cut/polished face that corroded or the prepped/unprepped area? In my 50 years of interest in fossils, you cannot tell which fossils will deteriorate - it mainly depends on the Pyrite formation. Paraloid may help but is no guarantee! The museums that can afford it,use the Ammonia method and vacuum sealing is probably the best method of preservation available at the moment.
Colin Huller
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