Moissanite carat weight vs diamond equivalent weight

Making sense of Diamond-Equivalent Weight (DEW), Carats, and Moissanite.

When shopping for jewellery, you may come across the terms "DEW", "carats" and its abbreviation “ct”. It can be confusing to understand what these terms mean, especially when it comes to moissanite. In this article, we will break down the concepts of DEW and carats in an easy-to-understand manner.


DEW stands for "diamond equivalent weight" and refers to the weight of a gemstone in comparison to a diamond. Gems are usually priced and sold by their weight rather than their size because it is a consistent and measurable characteristic, while size can vary based on factors such as cutting, style and angle. Different gems have different densities, meaning two gemstones can have the same carat weight but different sizes. DEW is used to compare their relative sizes.


Weight is directly proportional to the amount of material in the gem and is a fair and accurate way to determine the value of a gemstone.


Moissanite has a slightly different density to diamonds, meaning a moissanite and a diamond of exactly the same size will have a slightly different weight. Moissanite is a bit lighter than diamond, so will weigh less for the same size. For example, a 6.5mm round moissanite will weigh approximately 1 carat while a 6.5mm round diamond will weigh approximately 1.2 carats. We might then say that the 6.5mm round moissanite has a DEW of 1.2 carats to assist buyers in making the comparison between moissanite and diamond.


In conclusion, DEW and carats are two ways to measure the weight gem. Don't let technical terms confuse you – what matters most is finding the gem that brings a smile to your face every time you wear it.