Most commonly, fine gold is 999. This is the gold most commonly referred to as 24 karat gold, although technically 24 karat gold is 100% pure. However, as this is difficult to achieve outside of a lab environment, 999 gold is generally considered close enough. Gold manufacturers are legally allowed a half-karat tolerance in making gold products. Fine gold of this standard is also known as three nines fine. It’s seen in Chinese Panda coins, for example.

Below this is 995, the minimum amount allowed in Good Delivery gold bars. Two nines fine, or 990, is rarely seen, but still technically a type of fine gold. Beneath this is 986, also known as Ducat fineness. It is seen in historic coins hailing from Venetian and Holy Roman Empire mints, as well as modern Austrian and Hungarian coins.