Hi Rick,

Not an expert by any means, but according to Jeff "The Diceman" Laudeman, if your dice are crystallizing, but do NOT smell of vinegar, you can coat them with clear nail polish to help keep them from turning into a pile of dust. Dab carefully on the logo side, you're risking smearing the logo.

If they do smell like vinegar, nail polish will just make them sticky (from personal experience ...I had to try it out.)