How to Polish Gems of 7-8 Hardness: Survey Results
Some very popular jewelry stones, such as beryl, quartz, and topaz, fall in the 7-8 hardness range. You can find polishing recommendations for these stones in our IGS member survey results.
3 Minute Read
Editor’s Note: Some years ago, the International Gem Society (IGS) conducted a survey of members’ gemstone polishing techniques. In this article, you’ll find the results for polishing gems in the 7-8 hardness range. This range includes very popular jewelry stones, like emerald, quartz, spinel, topaz, and some garnets like malaia and mandarin. 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 7-8 Hardness
| Laptype | Polish | Lubricant | Votes |
| Tin | Linde A/Aluminum/Cerium Oxide | water | 19 |
| Tin | 50-100k diamond | oil or water | 17 |
| Ceramic | 50-100k diamond | oil | 13 |
| BATT | 50-100k diamond | oil or water | 8 |
| BATT | Linde A/Cerium Oxide | oil or water | 6 |
| Lucite | 50-100k diamond | oil or water | 5 |
| Dynalap | Cerium/Aluminum Oxide> | water | 5 |
| Last Lap | 14-50k diamond | oil | 4 |
| Lucite | Cerium/Aluminum Oxide | soapy water | 3 |
| Turbofan | water | 3 | |
| Copper | 50-100k diamond | oil or water | 3 |
| Tin | Linde A | oil | 2 |
| Cast Iron | 100-200k diamond bort | olive oil | 2 |
| Ultra Lap | Aluminum |
…
International Gem Society
Related Articles
How to Identify Synthetic Rough in Gemstone Parcels
Re-dopping a Stone
Color Change in Garnet
Gemray vs GemrayX Image Rendering
Latest Articles
Quartz Toxicity: Understanding the Risks for Jewelers and Wearers
Synthetic Amethyst: What is it and How is it Made?
Hambergite Value, Price, and Jewelry Information
Pearl Simulants: How to Spot Faux Pearls
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!