I was told by a commercial rock tumbler that he uses the green grade. supposed to be the best, but costs more.
Mohs on black is 9.2 and green 9.3 if memory serves. Increased cost may not be worth the tiny increase in grind.
He used the green. He purchased the green and his tumbling machines out of China. His name is
stonemaster499. His shop was in Madagascar.
Side note:
Nice SG chart
www.gemselect.com/gem-info/specific-gravity.phpZircon is the dense one. But almandine garnet is the cheapest yet high on the density scale.
Diamond is 3.5. Guessing synthetic diamond is 3.5. SiC is 3.4. SO, clay/kitty litter slurry will float the diamonds with no problem.
With 3.4 SG separating grit from a load of 2.7 SG quartz is easy with a lot of water.
Just dump rocks from rotary in a tray and wash them down with a hard fine spray till tray is full of water. Then pour off the top 2/3 and do it again. Maybe a third time.
All the 3.4 SG SiC will easily settle to bottom. Been there done that. Slurry will be thinned to almost water.
Pour rocks from tray and settled grit back into barrel carefully. Fill barrel to needed level w/fresh water. Add SiC as needed. Thickener as needed. Roll em again.
This method could be used to recapture 3.5 SG 30 grit crushed synthetic diamond for reuse.
It may be economical if the tumbling process does not break or dull the diamonds down.
There is a good chance the diamond will hold up for many loads due to their superior mechanical strength.
That schnitt is hard and impact resistant.
I would like to have a cup of synthetic diamond crystals crushed(so they would be sharp) to 30 grit size to try.
I use 1/2 cup SiC 30 for a 6-8 pound load.
How much would a cup of these crushed diamonds cost ?
I guess that would entail a search on Alibaba.
1 cup = 230 ml. 3.5 grams/ml = 230 X 3.5 = 800 grams = ~ 1.8 pounds. Is that correct ? Seems too heavy. I will weigh a cup of SiC 30, same thing @ 3.4 SG. No way a cup weighs 1.8 pounds.
Sharp broken diamonds like these, 20-30 grit so you can keep up with them at separation. $100-$200 for 1/2 pound(I think)
BUT, if you only needed to purchase a cup or a half cup and could reuse them 30 times....
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