The unit of measurement for a diamond is the carat. One single carat of diamond weighs 200 milligrams. A diamond's weight can also be quantified in terms of grains, whereby a four grains diamond refers to a one carat diamond.
The word carat is derived from the word carob which is a bean native to the mediterranean. Whenever a diamond weighed the same as a carob bean,the diamond was described as one carob,or one carat.
However in areas where the carob tree didn't grow for example the far east lands, diamonds were measured in terms of rice.Four grains of rice were roughly the same weight as a diamond, hence the descriptive term - a four grains diamond.
When shopping for diamonds, take care whilst buying mounted or set diamonds.This is because the tag on the jewelry indicates the CTW or carat total weight of the piece of jewelry and not the weight of each of the diamond pieces that are set on it.
This means that you might end up thinking that the carat weight of the diamond is high,while in reality the quoted CTW takes also into account the weight of the mount. Therefore it is upto the buyer to enquire from the jeweler the carat weight of the individual mounted diamonds.
