In Europe, 18kt and 14kt carat alloys are commonly used in jewelry, while 9kt gold is popular in Britain. Many countries require every item of gold jewelry to be clearly stamped with its carat value. This hallmarking system was developed in London in the 14th century at Goldsmith’s Hall. Some countries will also demand either for export or import purposes, that the country of origin be stamped alongside the carat value.
Have you ever noticed a series of numbers with a star eg. *1774 stamped on a piece of jewelry? This refers to the factory or designer where the piece was made. The *1774 number is the number allocated to the factory/supplier/designer when he/she registered his/her company.