Carat weight

For further details contact: 

Aesera Jewel Design Training Academy

No 144/74, Eskay Building, 3rd floor

Greams Road, Thousand Lights

Chennai -600006

Phone: +91-44-42027188

seshu.gopal@jewelcadcam.in 

Carat weight

A diamond’s weight is expressed in carats. Carat weight is the easiest of the Four C’s to determine. To get the exact weight however, the diamond must be loose. One carat is divided into 100 ‘points’ so that a diamond of 50 points is described as a half carat in size, or 0.50 carat. Within common weight ranges, there is little or no variation in per-carat price.

Cut

The cut of a diamond is also referred to as its ‘facets’ and relates to its proportion. Many cutters choose to sacrifice some of the diamond’s beauty to produce a stone that is a larger carat weight.
Cut, more than any other quality aspect, gives the diamond its sparkle. A diamond gets its brilliance and scintillation by the cutting and polishing of its facets, allowing the maximum amount of light that enters through its top to be reflected and dispersed back through the top.
With proper cutting the light passes through the top, bounces off the sides, and then travels back out the top, giving the diamond optimum brilliance. If the diamond is cut too deep, light passes through the side of the diamond. If the diamond is cut too shallow, light passes through the bottom of the diamond, also inhibiting maximum brilliance.
Two popular overall proportion indicators are Total Depth Percentage (D%) and Table Percentage (T%). D% is the diamond’s depth expressed as a percentage of its width (average diameter for rounds). T% is the diamond’s ‘table’ width expressed as a percentage of its overall width (diameters for rounds).

Round diamonds with cutting proportions within the range generally considered attractive, have depths from 55 to 63 percent; the table size of most round diamonds lies between 56 and 64 percent. With non-round shapes (‘fancy’ shapes), much greater proportion variations are encountered. In most fancy shapes, higher D% and T% are more common and are dependent on width to length ratios. See Round Facet Diagram below.

Colour

Diamonds come naturally in almost every colour of the rainbow. However, most people prefer diamonds in the white range. Colourless diamonds are more valuable, because they are rare. The lack of colour, or whiteness, in a diamond allows the light to pass effortlessly through the stone and disperse that beauty back to the observer.

The colour grading scale established by the Gemological Institute of America (GIA) varies from D (totally colourless) to Z (light yellow). D through F are virtually colourless. G, H and I diamonds appear colourless when mounted. J, K and L diamonds look very nearly colourless, but you can see some colour in larger stones.

Beyond M, most people can see colour pretty easily. The colour of the metal in a mounting can either mask or enhance the diamond colour. Yellow gold makes slightly yellow or brown diamonds appear more colourless. White mounting (gold or platinum) makes the colour more perceptible. See Colour Diagram below.

Clarity

Clarity describes the clearness or purity of a diamond, and is determined by the number, size, nature, and location of the internal (inclusions) and external (blemishes) imperfections.