Diamond cutting

In order to qualify as gems, stones must have beauty, they must be hard and tough enough to take considerable wear, and they must be rare enough for people to prize them. Diamonds, rubies and emeralds have all these qualifications and are the most prized gems. Gemstones, with only four exceptions, are minerals. These four exceptions are pearl, amber, coral and jet which are made of organic materials formed by plants or animals.

The beauty of the gemstone often depends on the way it is cut. The most crucial moment in diamond cutting is when the cutters make the first cut in the preparation of a fine gemstone. The slightest error or poor cutting could destroy or diminish the value of the diamond. With proper cutting, brilliant reflections should appear across the entire stone. These reflections also help to develop the strength of the color, in a stone, as well as its brilliancy. This method of cutting is called facet cutting and is used only with transparent stones. Experts may take months to plan their cutting of a great stone.

The cabochon cut is the method of smoothing and rounding out a stone. Long ago, before men learned facet cutting, all gemstones were given cabochon cutting. The only stones now cut in this way are opaque stones and stones with special cat´s-eye effects, asterism, or opalescence.