The 4Cs - Diamond Carat Weight
What Is Diamond Carat Weight?
A ‘carat’ is a unit of measurement used to weigh a diamond. Because even a fraction of a carat can make a considerable difference in cost, precision is crucial. In the diamond industry, weight is often measured to the hundred thousandths of a carat and rounded to a hundredth of a carat. Be careful not to confuse ‘weight’ and ‘size’. Weight refers to the carat weight, while size refers to the millimetre measurements of the diamond.
A diamonds carat weight is the most objective of the 4C’s as it involves no estimates, comparisons or judgments.
Diamonds are sold by the carat (shown as ct.)
Carat weight is unrelated to the similar sounding karat, which refers to gold's purity.
One carat is equal to 1/5 of a gram (0.2 gram) or 200 mg. One carat is equal to 100 points.
Diamond weights less than one carat are often expressed in points. For instance, a 0.75 ct. Stone would be described as ’75 points.’ it may also be referred to as a fraction of one carat – e.g. a ‘3/4 ct’ diamond. Diamond weights greater than one carat are expressed in carats and decimals. For instance, a 1.08 ct. Stone would be described as ‘one point oh eight carats,’ or ‘one oh eight carat.’
In jewellery pieces with more than one diamond, the carats may be described in terms of total carat weight. This is the combined total weight of all the stones in the piece and may be referred to as the total diamond weight (tdw or tcw) in the jewellery items description.
Why Is The Word ‘Carat’ Used For Diamond Weight?
The carat, the standard unit of weight for diamonds and other gemstones, takes its name from the carob seed. Because these small seeds had a fairly uniform weight, early gem traders used them as counterweights in their balance scales. The modern metric carat, equal to 0.2 grams, was adopted by the United States in 1913 and other countries soon after. Today, a carat weighs exactly the same everywhere in the world.
How Does Carat Weight Affect The Value Of A Diamond?
Carat weight is directly related to a diamond's value because, all else being equal, larger diamonds are rarer than smaller ones. Given the rarity of large stones, the price increases rapidly with size; therefore, a single 2 carat diamond will cost much more than two 1 carat diamonds. Large diamonds with good colour and clarity are very rare.
Even though the price of a diamond increases exponentially with the carat weight, the actual size does not.
What Size Diamond To Buy?
By itself, a diamonds carat weight may not accurately reflect the diamond's size. It is worth noting that carat weight does not determine the proportions or millimetre size of a diamond. Two diamonds of the same shape and exact same weight can have significantly different proportions which will make a very big difference in appearance, value, and price. To choose the best carat weight of a diamond, consider the size of the finger, the size of your setting, and your budget.
Not all settings will fit all diamond carat weights or shapes.
If you have already selected a setting, check the diamond specifications of your ring, or ask Australian Diamond Network for help.
If you need a special jewellery piece created, Australian Diamond Network can accommodate almost any request.
Australian Diamond Network