cal·i·per | ˈka-lə-pər
An instrument for determining the thickness or diameter of a gemstone
A caliper is a tool used by a jeweler to measure a gemstone. It is needed for several reasons. For example, if you are selling loose gemstones, you need to use a caliper to measure its size, as a gemstone’s size directly impacts its price. Alternatively, you may be making a piece of jewelry and need to measure gemstones to find the perfect fit for a ring, bracelet, necklace, or broach. Finally, you may be appraising a piece of jewelry with a gemstone of an unknown size, and need to measure the gemstone in the piece. Whatever you need for measuring gemstones, a caliper can help you measure its weight or size. Today, jewelers choose from either manual calipers or high-quality, digital calipers to measure gemstones’ weights and sizes. Calipers are a great way to accurately measure gemstones. To use them, you surround the gemstone with the jaws, tighten to fit, and read the measurement, which is typically displayed in the metric system.