The carat of a diamond is one of the most misunderstood aspects of valuing a diamond. It cannot be said that the bigger the carat the higher the value. In fact, the value depends mainly on the quality of the diamond; the clarity, color, and cut. All things being equal, yes, the bigger the carat the more valuable the diamond, but never are things all equal when it comes to diamonds.

Another misunderstanding of diamond carat is that it does not actually tell you the size, it tells you the weight. One carat (1 ct) weighs 1/5 of a gram and is divided into 100 points. Below you can see the chart for the weights of diamonds, however, diamonds are all unique and each diamond will have a very specific weight/carat.



 

Carat weight is the most common criteria inexperienced diamond buyers are aware of. The carat weight of a diamond is simply how much the diamond weighs. A carat is a unit of measurement equaling to 200 milligrams. Hence a 1.25 carat diamond will weigh 250 milligrams.

While the carat weight is certainly a factor when pricing out a diamond, it is by no means the end all. Many other factors must be considered including most importantly the quality of the diamonds cut. All factors (cut, color, clarity and carat weight) are used together to determine the value of a diamond. A shallow cut will lessen the value of the diamond due to the poor cut, but the diamond will have a larger diameter so that it 'appears' bigger. A deep cut diamond will have a smaller diameter than a ideal cut diamond, but will have a heavier carat weight since there is more volume (albeit wasted) to the stone. Assuming that we are comparing well cut diamonds to well cut diamonds, the price will increase dramatically as the carat size increases.