There are 45.52 carats on the hope diamond
Zero carats means that there is no weight to the stone. Perhaps that the stone is not a diamond? There is no notation for a diamond equal to zero carats.
The diamond weighs 112 carats, or 0.790136 ounces.
All the carats in the Hope Diamond are classified as blue-gray.
The phrase indicates that diamond(s) with a weight of 68 carats is the topic at hand.
45.52 CaratsThe Hope Diamond is 45.52 carats. By comparison the average engagement ring is only 0.3 carats.
The initials dwt may mean diamond weight total. In this case 6.80 is the weight measurement, in carats. The total weight is made up of several stones.
Carats.
The biggest carat in a cut diamond is 20 carats. The largest diamond ever found was 530 carats.
A round cut diamond weighing .25 carats measures 4.1mm at the girdle.
The notation '1.64 carat' means that the diamond weighs 1.64 carats.
According to Wikipedia, below, this diamond weighs "755.5 carats (151 g)."