A hallmark is the printed or perforated symbol that is hammered onto the surface of each piece of jewelry. The official distinctive sign provides information about the fineness of the precious metal. The regulations for the use of such trademarks are defined by law. The fineness number indicates how many precious metal parts are contained in 1,000 parts of the alloy. For example, "50" means that 750 units of pure gold are contained in every 1,000 parts of the gold alloy. (See also "karat.")

The 'Hope Diamond' is one of the most legendary gems of all time. Formerly the property of the French royal court, it is the largest blue diamond in the world and is believed to have originally weighed 112 carats. After being re-cut several times, it currently weighs around 45 carats. The diamond is believed to have been stolen from a Hindu temple in India and is therefore known to bring bad luck to its owner. A banker named Henry Philip Hope bought it in London in 1830. The jeweller Harry Winston gave the Hope diamond to the Smithsonian Institution in Washington, D.C. in 1958. It is on display there today.

The Hope Pearl is named after its former owner, a London banker named Henry Philip Hope. During the first half of the nineteenth century, H. P. Hope amassed a large collection of precious stones that included, among his other valuable objects, the famous Blue Hope Diamond. The baroque pearl Hope is cylindrical in shape, weighs about 454 carats and measures about five centimeters in length. Most of this pearl is white in color, although on the one hand the white hue changes to a bronze-colored tone.