Why do 50oz, 1kg, 20oz and 10oz cast gold bullion bars contain slightly less fine gold than their gross weight indicates?
According to the London Bullion Market Association, it is industry practice to state the weight of larger cast gold bars in terms of their gross troy oz weight. In the case of our 50oz, 1kg, 20oz and 10oz cast bars, the gross weight is comprised of the bar’s fine gold content (99.99% pure gold) and a tiny amount of impurity (silver). Example: To calculate the ‘fine’ weight of a Perth Mint 50 troy oz gold cast bar you can perform the following simple calculation: (weight) 50 x (fineness 99.99) = 49.995 troy oz. This figure appears in the bar’s table of Specifications in the field ‘Metal Content (Troy oz)’. Further Reading: For more information on this topic, please consult Bar Weights and Their Agreed Fine Gold Content in Troy Ounces on the London Bullion Market Association website. The ‘gross weight’ rule does not apply to other physical Perth Mint gold and silver bullion products on this website. Say you purchase a gold or silver bullion coin designated 1 troy oz, your coin actually w
