Check the listing for details. #1132 Natural Gold Nugget Australian 5.02 Grams Genuine. Listed at 976.40 USD. How are they weighed?. They are weighed by the troy ounces. The troy ounces are broke up into 20-penny weight to the ounces and use the symbol DWT or by the grams which have 31.1 to the ounces. The larger the nugget the more rare and valuable they are.