If you are shopping for a gemstone, one of the terms that you will surely come in contact with is the word carat. Carat, plain and simple is a unit of mass and weight. The measurement of carat was first used to only measure diamonds. However, since the terminology caught on, carat is now used to state the weight of many semiprecious and precious gemstones and minerals.
A carat is regarded as 0.2 grams. It should be noted that this measurement of weight is only for the total mass of the gemstone and has nothing to do with the gem’s quality or color.
Another term that you should be familiar with is TCW. This stands for Total Carat Weight. When diamonds or other types of gemstones are very small in size and usually included in a piece of jewelry as chips, instead of giving the measurement of each individual small stone, it is given a total weight of all the chips together.
It is also important to note that a rough diamond or gemstone is much larger in carat weight before it is cut. Usually through the cutting process, lots of lower quality materials are removed, especially inclusions if possible. The result is less mass, but usually a much prettier and higher quality stone.
Besides the term carat, there is also Karat. Karat is also a term in the jewelry business, usually associated with gold. Karat does not denote the mass or weight of gold, it denotes the purity.