Following take-in GSI weighs each item, using manual inspection and exact instrumentation, such as electronic balances or Sarin machines for loose gemstones.

Diamonds are weighed according to the international standard--to a thousandth of a carat. The weight recorded is rounded to a hundredth of a carat. When the thousandth place is 8 or below, we round down; when the thousandth place is 9 then we round up.

For example, the weight of 1.488 carats is rounded down to 1.48 carats.