When I was a kid we went on a trip to Derbyshire and spent a day picking up the rare Blue John mineral, even though it was apparantly illegal, and definately is nowadays. Recently I found the box again and figured I'd check the value, and turns out even very small, polished blue john pieces can easily go for £20-30, and I've got some pretty large ones. To think we only kept the ones that seemed to exist entirely out of the mineral...

Now I was curious how one would go about polishing them? I heard since it's so fragile blue john would need treatment prior to polishing. I'd appreciate any advice!