Before you buy: Important information on gemstone cut
When shopping for gemstone jewelry, the difference between precision cut gemstones and many native cut gemstones is not something about which most people are aware. However, when comparing a native cut gemstone with a precision cut gemstone, the difference can be very noticeable.
My name is Rogerio Graca. I am a professional gem cutter/lapidary and founder of Pristine Gemstones since 1991. Having been a gem cutter and a wholesale supplier of colored stones for over 28 years, I feel it is important to educate people about the “cut” in gemstones.
I work exclusively with a precision cut machine when cutting my stones. The main visible difference between precisio
n cut gemstones and native cut gemstones (stones cut in their native countries using traditional equipment) is the extra brilliance and appeal only seen in precision cut gemstones. Precision cut gemstones are cut at their correct refractive index using a digital precision cut machine, whereas many native cut gemstones are cut using rudimentary equipment that cannot accurately cut a gemstone at its correct refractive index. Note: Refractive index is the angle in the very bottom of the gemstone that corrects the bend of the light when it enters the gemstone. The correct refractive index of a gemstone allows light to be reflected back 100% and exit fully from the top of the gemstone (table) hence contributing to the highest possible brilliance.
Many native cut stones look dull and sometimes lifeless since they only partially reflect light. Usually these gemstones are cut very deep in order to retain weight, which also adds to the price of a gemstone without adding value (gemstones are sold by carat weight). Other times these gemstones are cut so shallow that light passes straight though the gemstone, giving the gemstone a “window”.
The introduction of precision cut machines in recent years has revolutionized the art of gem cutting allowing the gem cutter to unveil the inner beauty of every single gemstone like it has never been done before. Despite the introduction of the precision cut machine, over 95% of colored gemstones on the market today are still cut using traditional machines.
All of this being said about precision cutting gemstones, there are other considerations a gem cutter must make when cutting a gemstone to optimize its beauty and therefore its value. Every natural gemstone is unique in its exact color, clarity/inclusions, size, color centers, and other physical characteristics such as pleochrism (as in tourmalines). Therefore, not every stone will lend itself to being precision cut in every sense of the term, and each gemstone will require special attention in order to unveil its potential beauty.
Generally speaking, when it comes to cutting precious gemstones, it is a compromise between the ideal cut and considering all of the above mentioned factors with the ultimate goal of optimizing the beauty and value of the final piece.
For a guide to Gemstone Cutting terms please visit the following link to the International Gem Society