A measurement of weight that should only be applied to genuine gemstones.
As different gems have different densities, carat weights only have a loose bearing on the overall size of a gem.
The word originated from the Carob seed, which was once regarded as one of the most uniformed, naturally occurring items to be found on Earth, with each seed being similar in weight.
There are 5 carats to a gram and this measurement is now recognised around the world (even in the U.S. where the metric system isn’t used). In 1907, a carat became recognised as the international measurement for gemstones when it was adopted by the General Conference on Weights and Measures (an international body set up in 1875 to set measurement standards). Prior to this, many countries in Europe, Persia and the Middle East all had their own measurements for weighing gemstones: whilst they all seem to have been linked to the carob seed, they all varied slightly. If you have inherited a gemstone ring that is over 100 years old, there is every chance that the weight detailed on the certificate (jewellery certificates were even more prevalent in previous centuries) is incorrect.
