The weight of a diamond is measured in Carats. The word “carat” comes from the carob tree, whose seeds were used as the standard of weighing precious stones. Carat is often confused with size even though it is actually a measure of weight. It is important to know that 1 carat is equivalent to 200 milligrams. It can also be divided into 100 points. A quarter carat diamond or a 0.25 carat may also be referred to as 25 points.
 
 

In general terms, the larger the carat, the more valuable and sought after the stone will be. Since larger diamonds are found less frequently, a 1.00 carat diamond will cost much more than a 0.50 carat diamond, assuming colour, clarity and cut remain the same. It is important to note that the way a diamond is cut and mounted can make a diamond appear larger than its actual carat weight.