Carat refers to the weight of a Diamond and dates back to ancient times. It originates from the word Ceratonia siliqua, which is known as the Carob tree. Before scales were invented, Diamond Dealers and Jewelers would compare a Diamond to a seed from a Carob tree to determine the weight of the stone. Knowing that Carob seeds had a relatively uniform weight allowed those in the trade to determine how much a Diamond weighed without the need of a scale. Since then, it has become an agreed upon standard that one carat is equal to 0.20 grams. It is important to note that two Diamonds of equal carat weight can have different prices based on factors like clarity, cut, and color.