Gemstone. A jewel applied to a numismatic item for ornamentation or distinction, as rubies or diamonds applied to a decoration denoting gallantry or period of service. Those gemstones most desirable are precious stone; those of more plentiful in nature are semi-precious – both of these have been used on numismatic items, as well as imitation gems or synthetic gems, those made of glass or plastic. A gemstone can be faceted, shaped with many faces to enhance brilliance and reflect more light, or it can be a cabochon, without faces and entirely smooth. Gems differ in color and symbolism, indicating, for example, certain anniversaries.

Gemstone “dies.” Dies cannot be used to stamp gemstones, nor can dies be made of gemstones. Yet in the descriptions of a number of exhibited items in the 1910 International Exhibition of Contemporary Medals (particularly for French medalist Alphonse Eugene Lechevrel) six items are described: "from a die in sardonyx" (and six more are listed in a footnote as from "topaz dies"). The items are further described as galvanos. It is believed the original pattern for these were the engraved gemstones indicated. Perhaps it was lost in translation, but what should have been stated: "from a matrix or pattern made of sardonyx (or topaz)." The word die should not have been used.

References:

O6 {1911} ANS, p 177.