Traditionally, pure gold bullion is any gold which is 99.5% gold (also called 995 fine) or purer.  Various changes in the processes of refinement, specifically the Wohlwill Process has allowed refiners to achieve a 99.99% purity.  Although jewelry has allowed for the proliferation of other percentages of gold by mass, like 22k (91.70% gold by mass), 18k (75% gold by mass), 14k (58.3% gold by mass) and 10k (41.7% gold by mass), mixing metal by mass instead of volume only benefits the jeweler … think mixing lead and aluminum by mass instead of volume … you end up getting a lot more material with less lead because of weight.  Rather than sell customers art and jewelry of questionable volume and value, we make a Material Guarantee that we caste our jewelry only out of 99.99% pure gold, making our product a higher purity than even what is required for a 24k stamp in the US. Our gold is as close to gold in an elemental form as we can get outside a laboratory and is accepted as unarguable value anywhere in the world should you ever need to trade or sell it.