How does one measure loose pearls and necklaces?
9.A. For loose pearls weight is measured by traditional Japanese unit momme and kan. One momme is equal to 3.75 grams and also equal to 20.63 rati. The size of loose pearl is expressed by millimetre. But the length of necklace is measured in inches. This mix-up, interestingly, is accepted worldwide, so that one can say pearls are truly international product.