y putting the concentrate on a vibrating belt greased with fatty substances that are adhesive to diamonds. Further separation is done by optical selection with the use of photocells and x-ray technologies. On average one ton of diamond ore yields half a carat of diamond (one or more diamonds adding up to less than the volume of a pencil eraser). (Levinson 246) CuttingOnce the rough gemstones are extracted, they must be evaluated. The evaluation determines whether the diamonds are worth cutting for use in jewelry. Only about 20 percent of diamonds mined are used for adornment purposes. The rest of them are ground up and used for grinding wheels, glasscutters, milling cutters, and scientific purposes. The diamonds that are worth cutting are cut in a myriad of styles and shapes. The brilliant cut is the most common, as shown in figure one. Fig. 1. Brilliant cut diamond and ideal proportions; rpt. in GIA.There are several steps to cutting and polishing a diamond. The laps (cutting wheels) used in the process are all coated with diamond because the only material hard enough to cut diamond is another diamond. First, the rough diamond is cleaved. This means that the gemstone is sawn to prepare it for initial shaping. Once cleaved, the gem goes through the bruting process where it is given a shape with a girdle, crown, and pavilion. The final facets are then put on the gemstone and it is polished. The diamond is then ready for appraisal. (Levinson 238) Characteristics It is important to understand how the quality of a diamond is determined, and why some diamonds are more rare and valuable than others are. Value depends on quality, and the quality of a diamond depends on four characteristics called the 4Cs: Cut, Color, Clarity, and Carat weight. (GIA) What do these terms mean when it comes to buying a diamond, and is one "C" more important than another is? To make it simple, the larger the diamond, the rarer it is (carat ...
