Hi All, I now have more homework to do...finding out what your guesses are. I told you I am a humble opal guy...
My stone is Pollucite, a byproduct from Cessium mining to extract lithium for all those batteries we need. The material is extremely fractious. I had to treat it with starbond and cut it pretty thick...I think this cab was around 7mm thick. It is also very tricky to polish. I tried finishing it with pure cerium on leather..... no good....also ran it through the nova's to 14000....no cigar. Finally I used my diamond sprays on diamond sanding discs and polishing cloths...all the way from 1200 to 100,000 after taking it to 600 on the nova wheel. Not sure what all you guys use for tricky stones (undercutting etc), I suppose many of you are better than I am with this stuff.
I would be interested to hear from anyone that can get a good polish on Australian Marra Mumba tiger eye, which is pretty tricky. I get a pretty good polish on my diamond spray system, but it takes time and I am still not 100% happy with it, being the fussy soul that I am...as I suspect most lapidaries are!
Stay safe all. Our workshops are pretty good places to be right now!
Cheers,
Mike