Editor’s Note: Some years ago, the International Gem Society (IGS) conducted a survey of members’ gemstone polishing techniques. Here, you’ll find the results for polishing gems in the 4-6 hardness range. Stones in this range include species such as feldspar, fluorite, and apatiteWhether 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 information about the survey or to find results for more gemstones, click here.

Polishing Techniques for Gems of 4-6 Hardness


Laptype Polish Lubricant Votes
Ultra Lap Aluminum/Cerium Oxide vinegar/water 19
Tin Linde A/Cerium Oxide water 15
Lucite Cerium Oxide/Linde A water 13
Wax Alumina/Linde A/Cerium soapy water/water 7
Dynalap Cerium Oxide soapy water/water 7
Spectra (Ultra Lap) Cerium Oxide water 7
Lucite 50k diamond water 6
BATT Linde A/Cerium Oxide water 5
Tin 100k diamond vinegar/water 3
Tin 50-100k diamond oil 2
Copper 50-100k diamond Crysta Lubrication 2
CD Cerium Oxide water 2
Phenolic Aluminum/Cerium Oxide water 2
Spectra (Ultra Lap) Colloidal Silica vinegar/water 2
Raytech Fast Lap Cerium Oxide water 1
Raytech Fast Lap 50k