Gold is a valuable metal. Native gold ore, when mined, yields gold nuggets which can be smelted into gold bars.
Gold can be used for minting at a metalsmith's forge, creating coins used in the economy system. Using coins as trade goods is not advisable as they have no quality levels.
Another use of gold is to build furniture such as statues to be displayed all over a fortress, or to build roads and/or bridges of great value.
Making items from native gold only takes one gold nugget per piece, as opposed to three bars of gold metal.
If you possess native gold and galena or tetrahedrite, then consider making electrum bars over gold bars for a net increase in value.