How much is 10 grams of Gold 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 24 karat Gold?

Yes. Every figure here is for pure 24 karat (999) Gold. Jewellery is usually 14, 18 or 22 karat and is worth proportionally less: 22 karat is about 91.6 percent of this price, 18 karat about 75 percent. 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.