Diamond Carat Education

Diamond Carat

The weight of a diamond is measured in carats which is equal to 0.2g or 200mg. As the carat weight increases, the value also increases exponentially.

Although the weight of a diamond does have an effect on the size of a diamond, if a diamond cutter optimises the proportions from a rough diamond, when the finished polished diamond has been cut, the measurements of the diamond will often supersede the average size for its carat weight. Conversely, if a diamond cutter is aiming to retain as much carat weight in the polished diamond as possible, a greater yield from the rough diamond will have been achieved. However, the resulting polished diamond will possess excessive depth to it and due to its inferior proportions, it will not have been optimised for light interaction.

There are other ways to make a diamond appear larger, the setting of a diamond can change the way a diamond looks, for example, if a diamond is set high within a setting this can make the diamond appear larger.

History of carat weight

The word Carat came from the Greek word kerátion (κεράτιον), meaning carob seed, (literally ‘small horn’). It was used as a counter weight in order to measure the weight of precious goods, such as gold and gems, due to their consistent weight.

Sometimes known as metric carat, it was first adopted in 1907 at the Fourth General Conference on Weights and Measures.

Over size

Normally when a diamond is cut from its rough to polished form, the carat weight of a diamond usually reaches weights of, for example, 0.50 or 0.52, however these diamonds can sometimes be cut to weights of, for example, 0.79 or 0.99. These become over-sizes and sometimes known as mis-cuts (or ‘mistake stones’) as a diamond cutter would have been expected to reach the next carat weight bracket. These diamonds offer great value for money as they do not step into a different price bracket, yet may appear as large as stones in the next bracket up. This is why oversized diamonds are often referred as ‘financially intelligent.’



Diamond Size Chart

Diamond Image Size are displayed approximately.DiamondThe carat is a unit of mass equal to 200 mg (0.2 g; 0.007055 oz) and is used for measuring gemstones and pearls. The current definition, sometimes known as the metric carat, was adopted in 1907 at the Fourth General Conference on Weights and Measures, and soon afterward in many countries around the world. The carat is divisible into one hundred points of two milligrams each. Other subdivisions, and slightly different mass values, have been used in the past in different locations. Ref. Wiki

0.03cts (2.0mm) 0.05cts (2.5mm) 0.07cts (2.7mm) 0.10ct (3.0mm) 0.15cts (3.4mm)
0.20cts (3.8mm) 0.25cts (4.1mm) 0.30cts (4.5mm) 0.40ct (4.8mm) 0.50cts (5.2mm)
0.65cts (5.6mm) 0.75cts (5.9mm) 0.85cts (6.2mm) 1.00ct (6.5mm) 1.25cts (7.0mm)
1.50cts (7.4mm) 1.75cts (7.8mm) 2.00cts (8.2mm) 2.25ct (8.6mm) 2.50cts (9.0mm)
3.00cts (9.3mm) 4.00cts (10.2mm) 5.00cts (11.0mm) 6.00ct (11.7mm) 7.00cts (12.4mm)