How to Polish Gems of 4-6 Hardness: Survey Results

Polishing feldspar, fluorite, apatite, or other gems in the 4-6 hardness range? Our IGS member survey results can recommend some techniques and supplies.

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Home Learning Center Jewelry and Lapidary Lapidary and Faceting Guides, Tips and InstructionsHow to Polish Gems of 4-6 Hardness: Survey Results

By International Gem Society

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 apatite. 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 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

…

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