Asked in JewelryDiamonds
How big is a 5mm diamond in carats?
April 18, 2011 4:13PM
You're attempting to determine the weight of a stone given its measurements, which can not be accurate, since the two units of measurement are different.
Roughly, however, if the stone is round, it may weigh between .40 and .50 carat, if the 5mm measurement is at the girdle of the diamond.