NEED TO KNOW: DIAMOND CARAT
Though carats do have an impact on the size of a diamond, this member of the Four Cs is all about weight.
Carat (ct.) is the unique weight measurement for diamonds and other precious stones. Different gems have different densities, and as such, the weight of a stone will display its bulk in varying sizes. For instance, a diamond that is the same carat weight as a sapphire will be marginally bigger, because diamonds are not as dense.
As well as an individual gemstone’s carat weight, jewellers often refer to ‘total carat weight’ (t.c.w.). This is the combined weight of all diamonds or other gems that are included in a single piece of jewellery. For example, a diamond halo engagement ring’s total carat weight would include the central stone and those surrounding it, and a pair of diamond earrings would have their total carat weight calculated from both earrings in the set.