Picasso Jasper hopefully needs no explanation, it's the rock version of something Picasso might paint. However, I have a love/hate relationship with this stone. Let me explain...
An elderly french woman was selling her recently deceased husbands rock collection. Among the rocks was a chunk of picasso jasper that was perfect for slabbing. We agreed to a fair price and I took it home. It slabbed nicely and I was eager to made some killer cabs.
Now for the 'hate' part. It wouldn't polish. No matter what type of sanding/polishing method I used, it only produced a dull shine. Shortly thereafter, I was chewing the fat with an old rockhound in Orderville, Utah who had some highly polished picasso stone cabochons. I described my disappointment with my picasso stone and he proceeded to beat me about the ego with his 25 years of experience in cabbing. He never would divulge his method, other than I might achieve cabbing greatness after I'd put in my 25 years of dues.
I've since learned that there are different types of 'Picasso' stone. The formation (pattern) can be found in varieties of stone from sandstone to marble. It's all called the same thing, Picasso stone. I suspect that my version is of the sandstone variety, hence not a good candidate for a high polish. At least that's the story I'm using right now. Maybe someday when I've got everything else cabbed, I'll re-visit my picasso stone.