WHAT IS DIAMOND CARAT? “Carat” or “card number” means the weight of the diamond. Before the twentieth century, with all the weight of the diamond “carob seed” to measure, they are very uniform size and weight, the best tool is used to measure the weight of the diamond. The follow-carat diamond is the English “carat” from carob “carob”. Diamond Carat & Size DIAMOND CARAT VS DIAMOND SIZE( DIAMETER) Size is directly proportional to the weight of the diamond is saying. When diamonds are cut and polished to complete, it will be close to two-thirds of the weight loss. The high-quality, gem stone, the greater the more rare, so a single grains 2-carat diamond, one karat than two, the same quality of much more expensive diamonds. It increases the weight of a diamond, but it is looking up the diameter of the surface will increase, but add a lot of weight, just add a little diameter. For example: the perfect cut 1 carat diamond to its diameter of about 6.4mm wide, and when it increases the weight doubled to two carats, its diameter is about 8.1mm, but only less than 30% increase.