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Fineness of U.S. Mint Modern Bullion and Commemoratives
cameonut2011
Posts: 10,965 ✭✭✭✭✭
Years ago I thought the fineness of most precious metals used in modern bullion coins/commemoratives was .9993. The recent gold $250 has a fineness of .9999 and the Liberty $25 palladium coin appears to have a fineness of .9995. When did the Mint increase the purity of modern bullion pieces?
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I can’t say I don’t know the fineness from years ago.
it has never been that
theres been .999 .9999 and even .99999 gold [latter maybe never yet from the us mint but other world mints, notably Canada, have]
.925 and .999 silver
.9995 platinum and palladium
here's some info from google that might explain why you have this erroneous number in your head
"Why the number ".9993" keeps appearing online
If you browse third-party sales listings on platforms like eBay or certain coin dealer sites, you will occasionally see the American Silver Eagle or generic silver rounds listed as .9993 fine silver. This stems from two main points of confusion:
The Ounce-to-Gram Conversion:
A troy ounce equals roughly 31.1035 grams. The United States Mint specifies that a Silver Eagle contains 1 troy ounce of net pure silver, but its physical weight standard is written as 31.101 grams (with a legal tolerance).
In early digital inventory databases, some sellers or automated systems lazily divided numbers or miscalculated the ratio of pure silver to the coin's gross weight, accidentally outputting the decimal 0.9993."
Mostly from memory, with AI assistance on the gold....
Silver Eagles: .999
Silver coins in modern silver proof sets and modern silver commemoratives: .900, until they switched to .999
Gold commemoratives: .900
Gold American Eagles: .9167 (22-karat), but they weigh more than one ounce, so the net content is one ounce of pure gold.
Certain other gold coins, such as Gold Buffalos and some other issues: .999 (?) or .9999 (the "other" issues are because the Secretary of the Treasury has wide latitude to issue coins under the authorizing legislation for .9999 gold and maybe platinum).
I stand corrected on above fineness standards - thx @JBK