good video about cutting rough opal - from OA channel interesting technique using concave wheel
Re: Cutting Black Opal
Posted: Tue Dec 22, 2015 4:52 am
by PinkDiamond
I had seen the Empress opal in a still shot and wondered what it looked like with the color in play, so thanks for posting this OS.
I've never seen a concave wheel used before, and that's impressive how he cut that down so fast, and then worked the stone starting with 200 grit and moving on to 600, but I'm really surprised he apparently moved from 600 straight to polish. I also couldn't understand what he said he used to polish, either; all I could make out was that it wasn't cerium oxide so if anybody can figure out what he said, please let us know.
Re: Cutting Black Opal
Posted: Wed Dec 23, 2015 4:37 pm
by SwordfishMining
Real thin line between showing the bar and going thru a thin uneven layer. You only get one go is right. It always breaks thru the best color when you are using impact here it seems. The biggest opals are just rounded down to the best stone(s) possible losing tens of cts with each touch a few hundred dollars coming off with solid color like that. 80gms to cts. Said something like Websa for the compound. Local or new like Linde A or B is here.
I also couldn't understand what he said he used to polish, either; all I could make out was that it wasn't cerium oxide so if anybody can figure out what he said, please let us know. 