The diamond weighs one carat. Its other dimensions depend on its cut: round, princess, emerald and so forth.
A carat is 0.2 grams; a pure diamond has a density of 3.5 gm cm-3 which translates to a volume of 0.057 cm3 per carat. As stated in the first answer the linear dimensions depend on the shape that is cut.
It depends on the shape of a diamond. For e.g. the size of a round 1 carat diamond is width 6.55mm x height 6.53mm and oval 1 carat diamond has a width 5.98mm x 7.78mm.
A 625 carat diamond would be a very large diamond, weighing 625 carats.
A one carat diamond weighs one carat and contains one carat.
A one carat diamond weighs one carat, or .20 grammes.
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.
Today on Blue Nile, you can purchase a one carat SI1 diamond and pay about US$4,759; and a one carat VVS1 diamond and pay about US$12,252.
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.
These gemstones weigh the same: one carat.
First, understand that if your 'one carat' diamond has '80 points', it may not weigh one carat. Then, take your diamond to a certified gemologist who can tell you 'how much' can be attributed to your diamond.
Where ever you are in the world, a one carat diamond weighs one carat, or .20 grammes.
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.
A 33 carat diamond is rather large. Take your diamond to a certified gemologist and pay for documentation that covers not only its cut, but the clarity, colour and exact carat weight of the diamond.