Diamond - Carat weight

Diamonds were first discovered in India around 500 B.C. The first unit of weight used for diamond was the carob seed; the weight of a seed from the seed pod of the carob or locust tree was equivalent to a 1.00 ct. diamond.

Note: Do not confuse carat with karat. Carat refers to stone weight while karat refers to fineness of gold.

Determining the Carat Weight

The weight of a diamond is measured in carats. This is the easiest factor to determine. One carat is divided into 100 "points", thus a diamond with 75 points weighs .75 carats. However, two diamonds of equal weight may have a very unequal value, depending on their cut, color and clarity. Quality is not determined by weight alone.

Diamonds, today, are weighed using the metric system and the resulting weights are still converted into the carat as the unit of Diamond weight Devices used for calculating weight are the screw micrometer, the Moh gauge and the leverage gauge to mention a few.

Below is a graph illustrating Weight, in Carats, Diameter and Height.


Ct 0.05	0.10	0.20	0.25	0.30	0.40	0.50	0.70	0.90	1.00	1.25	1.50	1.75	2.00	2.50	3.00
Ømm 2.5	3.0	3.8	4.1	4.5	4.8	5.2	5.8	6.3	6.5	6.9	7.4	7.8	8.2	8.8	9.4
h mm 1.5	1.8	2.3	2.5	2.7	3.0	3.1	3.5	3.8	3.9	4.3	4.5	4.7	4.9	5.3	5.6

FAQ
Q: Beside the 4C's that all diamond websites inform me about, are there anymore specific ' details ' I should watch out for. And can they devalue the diamond?
A: I strongly recommend NOT to buy any weight that ends in .00 such as 1.00ct or 2.00ct.
We, the diamond traders look at these stones with suspicion because most of the times the polisher has had instructions to do whatever necessary to keep the stone from becoming 0.99 or 1.99 ct.
I have seen diamonds that still had a bit unpolished (rough) just to maintain the commercially interesting 2.00ct weight!

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