This thick mass of gold is still attached to its host quartz matrix which in most cases gets eroded away to leave the free nugget so common from the Aussie gold regions. Matrix specimens, with GOOD display quality to the gold, are very rare! This specimen is also from the area in Victoria where Australia's gold rush started over 150 years ago. Its total weight is 2.22 ounces / 69 grams. I have not done a SG test but a respectable part of the weight is surely gold