Carats and diamonds have been linked to each other for thousands of years. The modern carat system originated with early gem traders who would use carob seeds as counterweights in their balancing scales. At the time, each country had its own system and measurements would vary, but a universal agreement in 1907 officially made 1 metric carat = 200 milligrams.
Today, as part of the 4Cs, carat is still an essential part of determining the value of a diamond — and communicating that value to shoppers. Whether you’re shopping for an
engagement ring or the perfect pair of diamond earrings, here is what you should know about the role of carat weight in
diamond jewelry.