Carat is the only C among the 4 C’s that is not graded but measured in weight. Carat weight is used to measure the actual weight of a diamond – The unit of weight used for diamonds is the Metric Carat. Diamond weights greater than one carat are expressed in carats and decimals.
The carat has the same milligram weight in every corner of the world. It originated when the traders used Carob seeds to counterbalance the weight system.
A metric “carat” is equal to 200 milligrams and each carat is subdivided into 100 ‘points.’ This allows very precise measurements to the hundredth decimal place. A jeweller may describe the weight of a diamond below one carat by its ‘points’ alone.
The diamond price increased with the carat weight. However only carat weight cannot determine the price and value of the diamond depending on three other factors of the diamond 4Cs: Colour, Clarity, and Cut.
Due to modern technology, we at GII use an electronic device called Diamond Balance to weigh the carats that gives us an accurate weight of the stone. Our instrument is more than precise giving the weigh results in carats and grams enabling us to weigh diamonds up to 500 carats.
GII’s diamond cut grade considers the design and craftsmanship of the diamond, its weight relative to its diameter, its girdle thickness, the symmetry of its facet arrangement, and the quality of polish on those facets.
The GII Diamond Cut Scale for standard round brilliant diamonds contains 5 grades ranging from Excellent to Poor that balances between Brilliance and Dispersion.