NNP

Fineness.  The quality or purity of precious metal in numismatic or medallic items. In America fineness is expressed as a decimal part per 1.000, as sterling is .925; in Europe it is expressed as whole parts per 1,000, 925 is sterling. It may also be expressed as a fraction:  925/1000. It is required by law in most developed countries (England since 1904, America since 1906) to mark a precious metal item with its fineness. This is a modern expression, somewhat, of hallmarking which is a pledge of purity in a tradition which has been widely used for over 400 years.

Fineness is only applied to precious metals, as gold, silver, platinum. Such unalloyed precious metals are often too soft or unsuitable for practical use; they are alloyed with base metals for hardness or other properties. Sterling, again for example, is 925 parts per 1000 silver and 75 parts copper.

Unalloyed metal – solid metal – is often called fine; it would be assumed then that fine would be 1000 parts, but in actual practice commercially pure metal is only 999/1000 or .999 fine. German medal manufacturers mark their pure silver product as 1000. In America .999 is pure metal, and perhaps a but more accurate, as refining out that last 1 part per 1000 is very expensive. ("Four-nines" or "five-nines" precious metal can be obtained but it is mostly for scientific use and unnecessarily expensive for medallic purposes.)

A standard is an officially designated precious metal fineness, and numerous standards of fineness have existed throughout the world. Formerly the fineness in most countries was pegged by their coinage – as the composition of their major coin denomination was often the standard (sterling silver coins of .925 silver were struck in Great Britain from 1763 until 1919). For over 150 years .925 silver was both sterling and standard for Great Britain.

This has all changed recently with the defacto change in coinage compositions

throughout the world. Most countries, including the United States and Great Britain, have adopted clad metals for their circulating coins in a rampant debasement of coinage in the mid to late 20th century.

Likewise standards differ by time and place; sterling is .925 in British Empire countries, yet it is .935 in Israel. Coin silver is .900 in most countries, yet it is .830 in Germany and Scandinavian countries.

Reference:                                                                                                                               

B23  {1982} Kettell, Gold, p 105.

NE42 {1982} Doty, p 136-137.

excerpted with permission from

An Encyclopedia of Coin and Medal Technology

For Artists, Makers, Collectors and Curators

COMPILED AND WRITTEN BY D. WAYNE JOHNSON

Roger W. Burdette, Editor