Gem weight is measured in carats. Karate (called Carat, the abbreviation ct) - the measurement unit for measuring the polished jewelry and gemstone weight. In 1907. International Committee for Weights and Measures in Paris conference was a metric carat, equal to 200 milligrams (mg) or 0.2 gram (g). Before carat which the mass has changed, so the historical weight of diamonds can now cease.
In some countries (eg England, Switzerland), carat measurement system is used to measure the precious metal content of a pound of the alloy, we present a comparative-carat gold and sterling relationships:
24 carats - 999 fineness
22 carats - 916 fineness
20 carats - 833 fineness
18 carat - 750 fineness
15 carats - 625 fineness
14 carats - 585 fineness
10-417-carat fineness
9 carat - 375 fineness
8 carats - 333 fineness
Hallmark - The relative amount of precious metal alloy. The standard amount of precious metal, precious metal alloys on standardization by the International Organization (ISO) or by the standard unit of measurement that indicates the alloy from which the product is produced, and the relative value of precious metals in the alloy by weight of one thousand parts (ie, show how much precious metal is 1 kg alloy). The sign of the ratio (fineness mark) printed product. Precious metals include gold, silver, platinum group metals.
Assay - Precious metals and their alloys in the quality and quantity, as well as gems of identity and characteristics.
Gold fineness 375, 585, 750, meaning that 1000 alloy parts by weight (1 kilogram) is 375, 585, 750 grams of pure gold. Silver is usually 800, 875, 916 and 925 carat platinum - 950 fineness.
