How to Cut Gem Stones

Gems stones are cut and polished into shapes that show off their unique qualities in order to be set in jewelry. When dealing with gems like diamonds and emeralds, the technique is called faceting. There are several cuts that are possible to achieve using a combination of sanding, sawing, grinding, polishing and tumbling.

Things You'll Need

• Marbles or inexpensive stones for practice
• Lap
• Stone cutting or faceting machine
• Loupe
• Extra dops
• Slab or Faceting Saw
• Tweezers

Instructions

Learn to Cut Gem Stones

1. Check out the GIA (Gemological Institute of America) recommendations for diamond cutting schools (see Resources below). Cutting gem stones is a very precise talent, and these schools and classes teach the methods needed to properly facet while providing plenty of practice material.

2. Visit the Faceters.com website for information on faceting gems (see Resources below). The beginner's section includes suggestions for books to purchase, reviews of faceting machines and a starter's guide to cutting your own gems.

3. Practice cutting facets into gems on inexpensive glass marbles or pieces of quartz. This allows you to learn by trial and error, experimenting with different cuts, without spending a fortune on gems.

Cut Your Own Gem Stones

1. Verify what type of "cut" is needed for the stone you wish to style. There are several processes available for shaping a stone. Some stones actually melt away from the heat caused by a faceting machine.

2. Decide on the cut you wish to achieve. Popular cuts include brilliant, princess, emerald and heart, among others. Each style gives off a different brilliance, or sparkle.

3. Sand, grind or saw the chosen stone into the cut you desire. Follow the directions for your specific machine and guides for the cut you have chosen. In general, transparent stones should be faceted using a rotating lap, which is part of a faceting machine. More solid stones can be shaped with a saw.

4. Polish the cut stone using a metal oxide, such as aluminum. Polishing can be used to fine-tune the faceting of a stone. This is a great way to remove small imperfections or rough marks.

5. Mount the gemstone in a jewelry setting and enjoy wearing the newly cut stone.

Tips & Warnings

• You can spend thousands on a finely tuned faceting machine, or you can piece one together using common parts. For the most part, the more your spend on a machine, the better quality faceting you will achieve.

• In general, a cut gem stone is about 50 percent of the original raw material, so avoid practicing on valuable gems.

Resources

• The Gemological Institute of America (GIA) list of diamond cutting schools
• Faceters.com has a beginner's guide