How much is 10 grams of Silver in USD?

Look at the 10 gram row in the weight table above, or type 10 into the calculator. The value is simply the gram price multiplied by ten, since the price scales linearly with weight.

Is this the price of pure Silver?

Yes. Every figure here is for 999 fine Silver. Jewellery and cutlery are usually 925 sterling, which is 92.5 percent pure and worth proportionally less. Shops also add labour and margin on top.

Why is the world price quoted per ounce?

Precious metals trade internationally in troy ounces, which is 31.1034768 grams. Local markets quote grams instead, so this page shows both: the ounce price above the table and the gram ladder inside it. The troy ounce is not the everyday ounce of 28.35 grams.