Calibrated sizes refers to specific, standardized sizes of various gemstone shapes that are mass-produced for commercial jewelry purposes such as round, oval, emerald cut, pear shape, and more. Common calibrated sizes for ovals, pear shapes and emerald cuts would be: 6x4mm, 7x5mm, 8x6mm, 9x6mm, 10x7mm and so on. Round gemstones feature calibrated sizes starting at 1.0mm and generally can be found in whole and half increments, for example, 2.0mm, 2.5mm, 3.0mm, 3.5mm and up.
See Also: Melee