donchi519, If you are Listing 1964-before US silver coins, these would all be “.900 fineness.” Because they are 90% silver. The Kennedy Halves from the late 60’s that are 40% silver, these would be “.400 fine.” And Jefferson wartime part-silver nickels, having 35% silver, would be .350 fine. But as the others said, I wouldn’t worry about including fineness because apparently this is only (of limited) importance with Bullion Coins. With those, people don’t always realize that one ounce of gold or silver is one ounce of gold or silver, regardless of the fineness. If a bullion ONE OUNCE gold coin is .999 fine or .950 or .500 fine, there is always one ounce of gold—the rest of the coin is made-up of copper, nickel or whatever. Gold bullion usually has some silver in it as one of these “other metals.”The coin would need to be physically larger / thicker for .950 gold one ounce, vs. .999 gold one ounce. But still the bullion coin contains ONE OUNCE of gold. This is how all “historic gold or silver coins—not “Rare” but bought and sold to hold a “position” in gold or silver-are priced by dealers (and purchased by “investors.” You “do the math” and then you can figure out if a coin is priced reasonably (by using the percentage of gold in the coin and the current “spot price” of gold in the market.) The actual amount of the gold is computed and a few to several percentage points are then added as a fee / profit. Fineness = purity of the metal / the piece / coin. An easy way to figure fineness is if you know the percentage of say, silver in a particular coin, like a 1946 Roosevelt dime —90% silver—then just change this percentage to a decimal = .90. You then can add another “0” and it would be .900 fine. Usually fineness is given as three numbers to the right of the decimal point. Sometimes four numbers; .900 is the same as .9000. Any time you want to convert a percentage to a decimal, just “move the decimal point”2 places to the LEFT (90% — the decimal is considered to be where the % sign is, so “move the decimal point” 2 places to the LEFT and you have .90 (then add another 0 and you have .900). If you want to change a decimal number to a percentage, then move the decimal point 2 places to the RIGHT ( .90 or .900 would be 90%). If you really want to have fun LOL (I love Math and Numbers!! Haha) then convert a percentage number or a decimal number (90% or .90 for example) to a FRACTION. 90% would be 90/100, “reduced” it is 9/10. This just gives you a good idea of how much silver or whatever makes-up the coin. In this example, 90 out of 100 parts, or 9 out of 10 parts of the coin is silver. Sorry for the long answer, but after reading some of the comments I felt that I had to state some facts and explain a little. Bottom Line—you sound like you deal in rare and / or collectible coins. So fineness doesn’t apply to your coins. If you are Listing coins with silver content (or even gold) then giving the PERCENTAGE sounds appropriate to me. Like a 1950 Washington quarter you’d say is 90% silver. But other details are more important —as you know. Namely grade / condition, rarity, etc. So I think you’ll be “FINE” (haha) by NOT indicating Fineness in your Coin Listings! 👍
