Carats are used to measure a diamond's weight.
A jeweler can estimate the carat weight; a gemologist will remove the stone and weigh it, then give you a certificate that includes not only its weight, but its clarity, colour and the name and grade of the cut.
Diamonds are graded based on the 4 C's, cut, clarity, color and carat weight. A diamond is measured in two ways: carat weight and size. Jewelers use scales to determine the weight of a diamond, however the size of a diamond depends on the cut of it as it can impact how big or small a diamond may appear.
Every diamond is valued by its cut, colour, clarity and carat weight. A diamond this large is rare: you may be able to find a comparable carat weight diamond in an auction catalog from Sothebys or Christies.
You can browse the Tiffany site, below (without endorsement), to find the 48 carat diamond that you want to purchase from them. Otherwise a 48 carat diamond is a large diamond and may only be available from an auction house if you cannot find one at Tiffany's.
The carat defines the standard unit of weight measurement of a diamond.
Carat is the measurement of a diamond's weight. The stone's value would partially depend on its carat weight.
A one carat diamond weighs one carat and contains one carat.
A two-carat diamond is a gemstone that weighs two carats.
A 625 carat diamond would be a very large diamond, weighing 625 carats.
A half carat diamond of this cut measures 5.2 mm at the girdle; a .65 carat diamond measures 5.6 mm at the girdle. A certified gemologist can give you the exact carat weight of your diamond.
Carat is the weight measurement for gemstones.
There isn't any information on the smallest carat diamond ever sold. However, I did find the world's smallest diamond. It weighs in at 0.0003. It is being sent into the Guiness Book of World Records.
A one carat diamond weighs one carat, or .20 grammes.
One carat of diamond in carat total weight equals one carat. One thousand dollars worth of diamond in total carat weight depends on the cut, colour, clarity and individual carat weight of the stones in the group.