Updated: Oct 28, 2021
Know more about your jewellery- here is your guide to measuring gemstones and finding the perfect one for the setting you own!
How is a colored stone measured and how do I know which one will fit perfectly in the jewellery setting?
The ideal unit of measurement of gemstones is mm (millimeter) as different stones have different weights. For instance, a 5x3 mm Amethyst will have a different carat weight as compared to 5x3 Emerald. This is due to the variation in density and cut of each coloured stone. Thus, a 1.25 ct Amethyst setting can not be used for 1.25 ct of any other stone and settings are sold my mm and not the weight of the stone.
However, a buyer must look at both the size and the weight while making a purchase as the 'face up' sizes of stones have variances. Darker gemstones are preferred over lighter ones as they are more valuable and so each gemstone is cut in a different way to bring out the colour.
How do I measure a gemstone that is already set in a piece of jewellery?
Once a gemstone is mounted, it is not possible to get the exact weight and one must use estimation to find out the weight of the stone. Measuring the weight of the stone in an already set jewellery requires an expert to examine the stone and Amar Gems can provide the expertise. However, if you wish to measure the carat of your stone by yourself, you can refer to the below charts. These charts show conversion from mm to carats for standard sizes of various gemstones and gemstone shapes.