I have an old topaz crystal that a previous owner had painted with some kind of clear lacquer or varnish. I have tried soaking it in MTBE to dissolve the lacquer, but not all of it will come off. There are fine striations on the crystals and the lacquer is firmly adherent to these little crevices. I tried scraping it off with a wire brush and some Ajax cleanser, but no success. So now I'm thinking I should go to the hardware store and buy some paint remover. I doubt that paint remover would harm the topaz in any way, but I thought I would ask the experts before I go off on a misadventure.
Rock is correct about this, Topaz will be resistant to every organic solvent you through at it. I asked for a picture because the lacquer might also have been used to disguise/fill cracks. Removing the lacquer might cause your specimen to lose luster or fall apart. I suggest this possibility because I cannot think of any other logical reason why one would lacquer a topaz.Ok, another reason: The previous owner was bored.