Mike I am new at rock tumbling also. I have Petoskey stones also. I read that since they are a soft stone you have to be real careful. The book told how to polish by hand. I tumbled mine for about 24 hrs. I used a medium grit. By looking at them, I am afraid to put them back in the tumbler with the polish compound. My plan is just spray them with lacquer. I haven't done it yet. Hope this helps. I am sure someone who has more knowledge and maybe has tumbled Petoskey stones would have more info then me.
I also have what you call 'soft Petoskey stones'. I know those cannot go in the tumbler or be hand polished. The book tells me just to put them in a pretty jar with some mineral oil. I was thinking about trying to spray just one of them with the lacquer and see what happens.
Mike, petrosky stone, as far as I know is a calcite. The coral it originates from has not gone mineral transfer. Of the few petrosky stones I have tumbled, I have so degraded the stone with all the polishes I was left with very little. A stone polisher I know, saves the final polish for the petosky stones after he cabs the original shape. He routinely mass final polished all his cabs I have never been able to final polish my cabs so I use a leather buff and cerium or tin oxide. I suggest if you have some choice samples, put them aside. Larimar is also similar. Do not tumble Larimar. If the only way I could polish petrosky stone was to tumble, I would do 220 for a few days, checking constantly. I would move up to 660 for a week, and run at least two weeks with cerium oxide. There might be some non mineralized organics trapped in the centers of the coral cells. Watch for gas build up. I once tumbled some fossilized buffalo scat and the tumbler had a soupy green mixture. There was no odor, but I suspect the mineralization was incomplete deep into the stones. It leached out with the tumble. Just my perspective on this. I often wondered if the reason the petrosky stone is localized to the Great Lakes region and not near ocean shores is the wave activity and the softness of the stone. If some seem agatized tumbling might work. Just keep a watch on it.
In the beginning was the Floyd, and the Floyd was with Him, and He was with the Floyd. Syd Barret just disappeared, right after the happening. Lita Ford drives a suburban! Big Hair Heavy Metal is dead. Oh weeping and gnashing of teeth, the end is near. The answer is 42. 42! BING! BIG BING!
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hello its mike i just started my pre polish on my petoskey stones i did what you all said and that seams to work fine i left them in 14 houres with 300 then went to 400 ...14h. then 600. 14h. not done yet but they sure look prety good.... ;D thanks for all the help. ......mike
kimx5: Need help..have done everything to the rule week after week ...just took stones out after polishing process ...they look lovely while wet but they lose their shine when they dry out ...what have I done wt
Oct 19, 2014 12:29:56 GMT -5
kimx5: Ooopppss. ?.what have I done wrong I was going to ask ?
Oct 19, 2014 12:31:59 GMT -5
Fossilman: kimx5-go to the "Total Rock Tumble" site on this forum,you will get tons of help there...Not many people visit the "shout" page....Thumbs up
Oct 20, 2014 9:36:32 GMT -5
mr.mohs: only the mostly...mostly
Oct 20, 2014 10:51:57 GMT -5
Fossilman: He said he would,I said he wouldn't,but they thought he did,it turned out,he could have..............LMAO
Oct 21, 2014 9:15:14 GMT -5
hillquist: Just wanted to to the guy that was wondering about the Hillquist saw, it's a great saw, I have the 16 inch slab saw RF-14-16, the original Hill
Oct 23, 2014 20:09:45 GMT -5
Rockoonz: Hey hillquist I need the drum and clutch from the feed on a hilquist 24 inch saw.
Oct 23, 2014 23:41:03 GMT -5
drocknut: That's ok let em give me grief I got the rock so I'm happy.
Oct 24, 2014 20:48:50 GMT -5
wampidy: Grief? ? ? I aint givin ya no grief. I been givin ya humor. Did ya see where I said "she found it fair and square"? If that is grief what I give next will drive you mad as a hatter ya little squirt.
Oct 24, 2014 21:44:24 GMT -5
broseph82: Anyone with any extra arbors with hoods theyd like to get rid of on the cheap for a member? PM me please. thanks!
Oct 27, 2014 10:31:44 GMT -5
broseph82: Ill be slabbing some new BIG rocks today at the lab. Hopefully two of them produce some Paint Rock agate
Oct 27, 2014 10:32:32 GMT -5
snowmom: love coming to this site every morning, coffee in hand, and seeing what everybody has been up to.
Oct 30, 2014 6:23:49 GMT -5
wampidy: snow, what a plain Jane you are. Don't you know that us "in" people have moved up to cappuccino by Folgers and coming here with coffee of any sort and NO cinnamon and brown sugar pop tarts, I think, is a sin or something sinister.
Oct 30, 2014 8:37:02 GMT -5
wampidy: If I get up at my usual time, 4:30, we are here at the same time. Overslept today. Hmmmm the new cpap machine must be doing some good. I have not had this much energy in a long time. Catch 22, more energy, more doing, more back pain. Sucks but.............
Oct 30, 2014 8:43:22 GMT -5
snowmom: Jim, plain Jane plain black coffee... love that stuff. More energy good... naproxen works for me. Every day is a gift....
Oct 30, 2014 15:25:58 GMT -5
Fossilman: Black coffee,nothing better.................
Oct 31, 2014 10:03:45 GMT -5
mr.mohs: on the rocks!
Oct 31, 2014 10:10:00 GMT -5
rockpickerforever: Right back at ya, mohs! . I don't like blended because I hate brain freezes, and with on the rocks, I've got no blender to clean!
Oct 31, 2014 16:54:47 GMT -5