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.
3 Minute Read
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 |
…
International Gem Society
Related Articles
The White Paper Test and Rough Gem Buying
Odd Symmetry Designs for Gemstones
Faceting Survey Results – Polishing – Topaz
Faceting Survey Results – Polishing – Beryl
Latest Articles
Table of Refractive Indices and Double Refraction of Selected Gems
Red Gemstones: Ruby, Spinel, Garnet, and Other Great Picks for Jewelry
Jadeite Value, Price, and Jewelry Information
Tips for Cutting and Polishing Halite
Never Stop Learning
When you join the IGS community, you get trusted diamond & gemstone information when you need it.
Get Gemology Insights
Get started with the International Gem Society’s free guide to gemstone identification. Join our weekly newsletter & get a free copy of the Gem ID Checklist!