Diamond Weight Categories
Diamond Carat Weight
Diamonds are the heaviest and densest material known to man. Diamonds are weighed in carats. A carat is .2 grams. A gram of diamond would be a massive 5 carats. Very large in diamond terms although the actual diamond is small.
A carat is further divided into Points, and there are 100 Points to a carat. So 1 point is .002 of a gram. Very small indeed.
There is a scale of weight for Diamonds and this is shown here:
||Weight: pts (diameter)
Due to the minute differences in the weight of most diamonds they should always be accurately weighed on an electronic scale to the nearest 1000th of a carat (.001). Stones are always rounded up or down to the nearest 1000th of a carat by the way.
The other factor to consider with weight is a certificate. Where a diamond has been assessed and weighed at a laboratory, a certificate should be issued to confirm the assessment. No stones should ever be purchased without a certificate from a bona fide laboratory.
||Antwerp Diamond Laboratory
|AGA||American Gem Apraisal Laboratories|
|CSA||Jewellery Council of South Africa|
|DGL||Diamond Grading Laboratories (London)|
|EGI||European Gemmological Institute (Antwerp)|
|EGL||European Gemmological Institute (Antwerp & London)|
|PNF||P N Ferstenberg Pbv A|
|GAG||Gesellschaft fur Angewandte Gemmologie|
|GAN||Gemological Institute of Antwerp|
|GIA||Gemological Institute of America|
|GII||National Gemological Institue of Israel|
|GIL||Gem Information Laboratory|
|GTL||Gem Testing Laboratory of Great Britain|
|NGL||Northern Gemmological Laboratories (UK)|
|HRD||Diamond High Council (Antwerp)|
|HRG||Heinz R Gartner, DGemG, FGA (Germany)|
|IGI||International Gemmological Institute (Antwerp)|
|PSL||Precious Stone Laboratory (London)|
|VPT||Verena Pagel-Theisen, DGemG FGA (Germany)|
|WG||Werner Galia, DGem, (Germany)|
It cannot be iterated enough to ensure that all diamonds you buy should have a certificate from one of the above laboratories.
See also Diamond Appraisal
More information on carat weight can be obtained here Weight of Diamonds