Carat TW stands for carat total weight. It is the combined weight of all the gemstones in a piece of jewelry.
A carat is a unit of weight used to measure gemstones. A gemstone is any precious or semi-precious stone used in jewelry, such as a diamond or a sapphire. The definition of a carat has changed through the years, but today the standard weight for one carat is 200 milligrams, or 1/5 of a gram. This system has been in place since 1913.
It is important to note that carat measures weight, not size. Sapphires, for example, are denser than diamonds, meaning that a sapphire and a diamond with the same carat weight will be different sizes. A carat is divided into units of measurement called points. There are 100 points in a carat, meaning that a half-carat stone has 50 points. Jewelers often discuss carats in terms of 1/4 carat increments.
Carat TW is only one determining factor of a gemstone’s worth. Typically, a larger stone is worth more than a collection of smaller ones, even if the total weight is equal.
Carat should not be confused with “karat.” Karat is a measurement of the purity of gold. Pure gold, being a soft metal, is rarely used in jewelry. Instead, alloys are used. A karat measurement describes how much gold versus how much alloy is in a piece of jewelry.Learn More
The diameter of a one-carat round or brilliant cut diamond typically measures between 6.4 and 6.5 millimeters. The term carat refers to weight not size, so a one-carat diamond doesn't need to conform to specific measurements.Full Answer >
A 2-carat diamond has a width of 8.2 mm in the round brilliant cut. However, it is important to remember that 2-carat diamonds with different cuts typically have differing size measurements.Full Answer >
The average cost of a half-carat diamond is between $1,500 and $2,500, as of September 2014. While size is an important factor, cut, color and clarity also play a role when pricing diamonds.Full Answer >
Individual diamond prices vary and depend on the characteristics of each stone. Established in the 1940s, the grading system currently in use weighs each stone's color, clarity, cut and carat weight in determining its price.Full Answer >