polishing corundum - Barion cut sapphirepolishing corundum - Barion cut sapphire

Corundum Polishing Survey Results

The corundum gem family includes ever popular rubies and sapphires. Our IGS member survey results offer some corundum polishing recommendations.

3 Minute Read

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 corundum polishing. The corundum gem family includes both ruby and sapphire. 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.

Check out these articles for additional recommendations for polishing sapphires and polishing synthetic corundum.

Corundum Polishing Techniques

Ceramic50-100k diamondextender/oil44
Tin14-100k diamondwater, vinegar/oil13
BATT50-100k diamondoil or water8
Ceramic50-100k diamondnone/alcohol/other8
Fast or Last lap14-50k diamondoil/water7
Copper50-100k diamondoil6
Cast Iron100k diamondbaby oil/kerosene/olive oil/extender5
Ceramic50-100k diamondwater4
Zinc50k diamondoil3
Corian14k diamondoil2
Marine Brass50k diamondoil2
Turbofan Corundumwater1
Plexiglass14-100k diamondoil1
Mirror FacetMirror Facetwater1


  • Polishing agents and lubricants divided with a “/”, like “cerium/diamond,” means either/or.
  • Polishing agents

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