Not Only Carats Matter
One carat (abbreviation ct) is equal to 0.20 grams. Only one in 1,000 diamonds weighs more than a carat.
Two diamonds of the same carat weight may have different prices based on their colour, clarity and cut. A heavier diamond isn’t automatically more valuable.
Since larger stones are rarer than smaller ones, diamond value rises exponentially with carat weight. Therefore, a diamond weighing 3.0 carats, will always be worth more than three 1.0 carat stones of the same quality.
The less colour – the higher the value
Colourless and near-colorless diamonds are the most valuable. (The exception to this is fancy color diamonds, such as pinks and blues, which lie outside this colour range. Prolink to fancy diamonds chapter)
The scale begins with the letter D, representing colorless, and continues with increasing presence of yellow color to the letter Z. Many of these color distinctions are so subtle that they can only be recognized by a professional under controlled lighting and precise viewing conditions.
These slight differences make a very big difference in diamond quality and price. Depending on the stone’s size, a single increase in color grade can boost the value of a diamond by thousands of dollars per carat.
The Clarity of a diamond is based on the number, location, size, and type of inclusions found in the stone. An inclusion is an imperfection in the stone that is visible at ten-time magnification.
Pure diamonds are extremely rare, and almost all contain “inclusions” or impurities. These are caused by the incomplete crystallization of carbon or other minerals that were trapped in the mineral during the stone’s formation. These imperfections are purely natural and highlight the uniqueness of each diamond.
Perfect cut = more sparkle, brilliance and fire.
Precise workmanship is required to cut a diamond so its proportions, symmetry, and polish maximize brightness and fire. If the diamond is not well cut, it will not interact with light as it should.