A few years ago, I tried to etch some apatite beads. After I was done, they were so fragile they broke at the slightest touch. Russ Nobbs explained here that their chemical makeup made them ineligible for etching.

Now I'd like to etch some Mexican onyx beads I picked up at the flea market last week. Does anyone know if this will work, or if it will destroy the beads? (I know I could test one, but just wondering if anyone knows for sure.)

I will always miss Russ!!