Editor’s Note: Some years ago, the International Gem Society (IGS) conducted a survey of members’ polishing techniques. Here, you’ll find the results for opal polishing. Whether you’re just starting to learn the art of gem cutting or just looking for a new way to tackle a problematic gem material, we hope these results provide some useful suggestions.

For more opal polishing recommendations, see the survey results for gems with 4-6 hardness.

For more information about the survey or to find results for more gemstones, click here.

Opal Polishing Techniques

Lap Type Polish Type Lubrication type Votes
Lucite Cerium Oxide water 19
Tin Linde A water 17
Ultra Lap Cerium Oxide water 14
CD Cerium Oxide vinegar/water 8
Dynalap Cerium Oxide water 6
Polypad Cerium Oxide water 5
Tin 50k diamond olive oil 4
Copper Diamond Crystalube or similar 4
Turbofan Cerium Oxide water 2
Ceramic 100-200k diamond 2
BATT Cerium Oxide water 2
Corian Cerium Oxide 1
Lucite 14k diamond DiaLube 1
Brass 50k diamond water 1
Diamond Pacific Diamond water 1
Tin 50k Diamond water 1
Felt 50k/Linde A mix water 1
Spectra (Ultra Lap) Cerium Oxide Colloidal Silica 1


  • Polishing agents and lubricants divided