Pdwight
has rocks in the head
Member since June 2003
Posts: 619
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Post by Pdwight on Nov 28, 2003 14:18:16 GMT -5
I have some Aventurine that I have been trying to polish for 2 months now...uuuuggggghhhhh It took a little shine..but not like the agate..I mean it is really matt finish...am I missing something ?? I did 7 days in 40 grit , 7 days in 120 Grit , 7 days in 500 Grit , and 3 weeks in Cerium Oxide with fresh virgin plastic pellets !?!?!?
The only clue was I added a few pieces of Ocean Jasper in the final polish to finish them off as well.....HELP
Dwight P
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SirRoxalot
freely admits to licking rocks
Member since October 2003
Posts: 790
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Post by SirRoxalot on Nov 29, 2003 12:47:04 GMT -5
I've seen very nicely polished aventurine and I've seen some pretty lousy tumbled stuff as well. I can't positively say what's going wrong with your polish, but I can offer some clues.
I'd suggest not mixing stones, for one, ocean jasper is probably harder and tougher than aventurine. Very, very careful pre-polish cleaning might help, grit transfer ruins the polish. Maybe double the time in 500 grit.
Also, there are different grades of aventurine, some types might not take a polish. I just got a mixed sample box of the stuff, I had high hopes but it's all over the map, three colors and varying composition; only one piece of the dozen would I even try to tumble.
Hope this helps a bit.
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Post by docone31 on Nov 29, 2003 20:15:34 GMT -5
Aventurine is a feldspar, a cryptocrystaline. I too have had trouble with polish. I have tumbled, and some have positively shone, I have also had some just look dull. I have faceted aventurine and on a phenolic lap with cerium oxide it is great. These have been smaller meet-point facets, and I think the flat plane, combined with pressure does the trick. I have been tossing that one around. I get to speak with a retired lapidariest where I have my shop. He tumbled finished cabachons after shaping. He also hand polished cabs. He thinks aventurine needs dry polish. You are not alone.
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