Diamond Weights and Sizes
Diamonds used in jewellery are measured in carats. This is a unit of weight. One carat of diamond weight is equivalent to 0.2 grams.
The visual size of a diamond depends upon the shape of the diamond and the way it is cut. For example, a diamond with a large flat top surface will look larger than a round brilliant diamond with its small top surface and deep profile even when the carat weight is exactly the same.
If you want to buy the largest looking diamond within your budget, choose an oval shape or marquise cut. These shapes may not sparkle as well as a deeper cut round brilliant but can look impressively larger.
The carat weight quoted for diamonds in a piece of jewellery is for the combined weight of all the diamonds used in the item. This also applies to earrings where the weight quoted is for all the diamonds' combined weight in both earrings.