How to Cut Emeralds

An emerald is a valuable gemstone with a hard but brittle consistency.

An emerald is a rare and valuable gemstone popular with the high-end jewelry market. The process of cutting gemstones is known as "lapidary," or more simply, "gemcutting," and is usually undertaken by a trained professional. Before a gemstone is cut and polished, it is referred to as "rough," whereas after it has been approximately whittled to discard excess debris and to form a vague shape, the gemstone is said to have been "cobbled." Emerald is a hard but brittle gemstone, and as such the cutting of emeralds is usually undertaken by expert gemcutters.

Things You'll Need

• Gemstone scanning equipment
• Cutting/abrasive equipment: slab saw, trim saw, faceter's trim saw (steel construct with diamond edging)
• Workbench
• Desk lamp
• Polishing equipment (diamond mesh, aluminium oxide, tin oxide or silicon dioxide)

Instructions

1. Review the color, hue and quality of your chosen emerald. Most gemcutting experts use computer technology to analyze their gemstones and to determine how the gemstone should be cut. Scanning equipment can be very expensive, and it may be more financially viable to outsource the scanning procedure to a specialist scanning company who will be able to send you a report detailing your gemstone's weight, dimensions and the inherent quality of the stone itself. This information will help you to decide how to treat (i.e. cut and price) the emerald. It is advisable to use professional scanning equipment if you wish to maximize the value of your finished emerald.

2. Choose a cut for your emerald, once you have the results of your emerald's scan. The quality and composition of the emerald will play a decisive role in the gemcutting process. Common cuts of gemstones include the Emerald Cut, the Princess Cut, the Baguette or Pyramid, the Heart Cut and the Pear shape.

3. Remove unwanted residue. Place the gemstone in a holding platform so that the gemstone is stable and there is no risk of it moving; emeralds are brittle stones and are particularly susceptible to damage by scratching. Once the gemstone is held in place, sand away the rough using a series of different saws. The slab saw can be used to cut away large sections of unwanted stone or to cut the emerald into several different, smaller sections. Cobble your emerald down to a rough approximation of the final cut.

4. Clarify the emerald. Using a trim saw, which is often 6 to 10 inches in diameter and has a very thin, precise blade, cut away at your emerald in line with your chosen cut and design. The trim saw is used to cut smaller sections of slab from the stone, or for where you need a higher degree of accuracy. Use a faceter's trim saw for the smallest cuts of rough that are of high value and require the highest degree of accuracy and focus. Once you have finished the cutting stage, your emerald should look like an unpolished version of a finalized product.

5. Polish your emerald. Polishing agents on the market include diamond mesh, aluminium oxide, tin oxide and silicon dioxide; each will bring out an appealing luster in your emerald. To polish the emerald, cover it in the abrasive powder of your choice and dust until the remaining unwanted portions of stone are removed and a shiny surface is revealed below.

Tips & Warnings

• An emerald is a tough stone to work with for beginner gemcutters. If you are just starting out in your gemcutting hobby and are not yet skilled to a professional standard, you may wish to choose an alternative stone. For example, tourmaline, tsavorite (garnet), chrome diopside or peridot will be easier to manage.

References

• Beginner's Guide: How are Emeralds Cut and Polished?
• Tradeshop: Lapidary Techniques
• Gem Scan Laboratories: Home
• Khulsey: Gemcutting Technology
• Gemstone Artist: The Gemcutting Process