The Diamond Certification Laboratory of Australia (DCLA)
Buy and sell diamonds with the help of the experts
The standard unit of measuring the weight of a diamond. The origin of the word traces back to ancient times when diamonds were weighed on balances against carob beans, which held a consistent weight. One carob bean, or carat, weighs 1/5 of a gram.
Diamonds are made of pure carbon that has been subjected to and crystallised under enormous heat and pressure. Without the pressure, graphite is formed instead of diamond. Other forms of carbon can be found in substances like coal, but these are impure forms of carbon.
Small black graphite inclusions in a diamond. Diamonds are made of pure carbon that has been subjected to and crystallised under enormous heat and pressure. At times, not all of the carbon crystalises, and small black spots may remain.
Term used to describe an intensely or vividly bright-yellow fancy colour diamond.
A broad scale of diamond colour grades that ranges from a near colourless, almost undetectable pale yellow to increasingly tinted yellow. Once it has enough yellow saturation to qualify as a fancy colour, it is no longer called a Cape Series diamond.
Diamond cut or shaped to look like a triangle with all three corners cut off, similar in outline to the head of a calf.
A blemish on the surface of a diamond that looks like an oily or frosted area. When a diamond is polished too quickly, heat from excessive friction builds up and leaves a mark on the surface. Burn marks affect the polish grade of a diamond.
Diamond cut or shaped into a full tear-drop with a circular cross section; briolettes are generally covered with triangular facets.
A style of diamond cut, using triangular or kite shaped facets that radiate out from the center of the diamond to the girdle. The standard round brilliant cut consists of 32 facets plus a table above the girdle and 24 facets plus a culet below the girdle. Other shapes besides round can be faceted as brilliant cuts, including marquise cut, oval cut, pear cut, heart cut, and radiant cut diamonds.