A common misconception when it comes to diamonds is that carat refers to size. In fact, carat refers to the weight of the diamond, one metric carat being equal to one fifth of a gram (0.2 gram).
The origins of the word carat is actually from the carob seed. These seeds were thought to have very little variance in weight and were therefore used as the standard counterweight on the scales of gem traders.
A carat is then further broken down into “points”, 1 carat being equivalent to 100 points. Ever hear of someone referring to a 50 pointer? They would be referring to a half carat diamond.
When weighing and measuring diamonds, precision is key, as even a fraction of a difference in weight can translate into enormous cost differences. One might wonder why the value of a diamond increases exponentially as it increases in carat weight. The reason is its relative increase in rarity. Vast quantities of ground must be mined to produce enough gem-bearing rock to produce a single 1ct polished diamond.
Two diamonds of identical carat weight can have very different values, depending on the rest of the 4C’s (their Cut, Colour and Clarity). For some people looking to purchase a diamond, carat weight is the most important of the 4C’s.
With a poorly cut diamond, much of the weight may be hidden in its depth. One with a better cut will have a larger diameter and therefore be perceived as larger in size. That’s why it is so crucial, when purchasing diamonds, to ensure your gemstone has the best proportions.