I got around to working with the rhodochrosite again.
It seems that the non-diamond grits smooth more than scratch away.
Anyway, I tried different things with the four stones.
#1 stone - I took it through a 1200 grit polish. The scratches showed up again. So on rhodochrosite it isn't a matter of a grit inbetween 600 and 1200. It is that the 1200 cuts pretty deep into rhodochrosite.
#2 stone - From the tripoli polish I took it through a 14K grit polish. I started on the outside of the pad and that put in scratches. After moving near the center I was able to get rid of most of the scratches I put in and get near the tripoli polish.
#3 stone - From the tripoli polish I took it through a cerium oxide polish. This improved the tripoli polish a great deal. But the finish was just a wee bit hazy.
#4 stone I set aside to mull my options.
I'm starting to think that taking the stone down to a 14K grit polish and then over to the cerium oxide might be best. I say this because even if the diamond does put scratches in the stone, it prepares the surface to take a better polish.
What I'm wondering now is should I do a tripoli polish inbetween the 14K grit and the cerium oxide. That would definitely get rid of all scratches, but it might rough up the 14K grit's work. Perhaps I'll test that if the 14K grit to cerium oxide doesn't work.
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AH HA!!
Scroll near the end of that and click through next in thread.
OK, so soft stone is issue #1 with regards to high gloss finish. The other is speed.
The two stones I ran through the cerium oxide were done on the outside of the wheel.
So... what now?
I've taken these stones to 14K twice and then up to a tripoli polish. One of the threads in the link above indicates that a 600 grit sanding is sufficient before a slow cerium oxide polish.
I think I'll next work all the stones through cerium oxide on the inside of the pad. The next three stones are larger rhodochrosite that I'll try taking down to 600 grit before moving to the polish.
I also poked around google images looking for some finished rhodochrosite being sold. I think I was expecting a better finish than the stone can give.
If these stones work out I think I'll have to hunt around to find out how to get rid of the final scratches in my moonstone. I suspect that a good run through with the cerium oxide might do the trick.
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