Seventy-five/one hundredths of a carat in gemstone weight equals three quarters of 0.00705479239 ounces, which is the ounce weight of one carat. In grams, a .75 carat diamond weighs three quarters of 0.2 grams. Can you do the math?
The value of a diamond depends on its cut, its clarity, its colour and its carat weight. A local jeweler can give you the answer you want.
A 6mm stone would be a.75 carat diamond.
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.
A carat is a standard unit of measure that defines the weight of a diamond. One carat is equivalent to 200 milligrams. Carat sizes are also expressed as “points”, with a one carat diamond equaling 100 points, a one-half carat diamond being 50 points, a three-quarter carat diamond being 75 points, and so on.
The weight of a carat is equivalent to 200 milligrams, so a two-carat diamond weighs 400 milligrams.
The diamond either weighs 100 points, or a full carat, or it weighs 80 points or 80/100ths of a carat.
Two tenth carat isn't a term usually associated with a diamond. Every diamond is priced according to its carat weight, its colour, its cut and its clarity.
Any diamond is worth whatever someone will pay you for it. Today, on Blue Nile, you can purchase a diamond of this approximate carat weight and pay between US$1,508 and US$4,981, depending on the cut, colour, clarity and exact carat weight that you want.
A carat is a measurement of diamond weight. From Amazon.com: "Carat is the unit of measurement used to describe the weight of diamonds. One carat is equal to 0.2 grams, or 0.007 ounces (avoirdupois). Five carats equals 1 gram, and 141.7 carats equals 1 ounce."
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.