Millesimal fineness
Millesimal fineness is a system of denoting the purity of platinum, gold and silver alloys by parts per thousand of pure metal by mass in the alloy. For example, an alloy containing 75% gold is denoted as "750". Many European countries use decimal hallmark stamps (i.e. '585', '750', etc.) rather than '14K', '18K', etc., which is used in the United Kingdom and United States.
It is an extension of the older carat (karat in North American spelling) system of denoting the purity of gold by fractions of 24, such as "18 carat" for an alloy with 75% (18 parts per 24) pure gold by mass.
The millesimal fineness is usually rounded to a three figure number, particularly where used as a hallmark, and the fineness may vary slightly from the traditional versions of purity.
The most common millesimal finenesses used for precious metals:
Platinum
- 999 (also known as three nines fine)
- 995 (what most dealers would buy as if 100% pure; the most common purity for platinum bullion coins and bars)
- 950 (the most common purity for platinum jewellery)
- 900 (also known as one nine fine)
- 850
Gold
- 999.999 (The purest gold ever produced. Refined by the Perth Mint in 1958.)[1][2]
- 999.99 (The purest type of gold in the market)
- 999.9
- 999 (Fineness equivalent to 24 carat, also known as three nines fine)
- 995 the minimum allowed in Good Delivery gold bars
- 990 also known as two nines fine
- 958.3 (equivalent to 23 carat)
- 916 (equivalent to 22 carat)
- 833 (equivalent to 20 carat)
- 750 (equivalent to 18 carat)
- 625 (equivalent to 15 carat)
- 585 (equivalent to 14 carat)
- 417 (equivalent to 10 carat)
- 375 (equivalent to 9 carat)
- 333 (equivalent to 8 carat; minimum standard for gold in Germany after 1884)
Silver
- 999.9 (Ultra-fine silver used by Royal Canadian Mint in the Canadian Silver Maple Leaf)
- 999 (Fine silver used in Good Delivery bullion bars, also known as three nines fine)
- 980 (common standard used in Mexico ca.1930 - 1945)
- 958 (equivalent to Britannia silver)
- 950 (equivalent to French 1st Standard)
- 925 (equivalent to Sterling silver)
- 900 (equivalent to Coin silver in the USA, also known as one nine fine)
- 833 (common standard used in continental silver especially among the Dutch, Swedish, and Germans)
- 830 (common standard used in older Scandinavian silver)
- 835 (a standard predominantly used in Germany after 1884)
- 800 (minimum standard for silver in Germany after 1884; Egyptian silver; Canadian silver circulating coinage)
- 750 (uncommon silver standard found in older German, Swiss and Austro-Hungarian silver)
See also
References
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