By comparison, annual worldwide platinum production is approximately 160 tons as opposed to 1,500 tons of gold from just a handful of regions of the world succumbing to an arduous and time-consuming mining and refining process. A single ounce of platinum requires about 10 tons of mined ore followed by a five month refining process. Platinum used in the manufacture of jewelry is actually an alloyed group of six very similar heavy metals, including platinum, palladium, rhodium, ruthenium, iridium and osmium, most of which were not even distinguished from each other until early in the nineteenth century. Often alloyed with copper and titanium, platinum, is the only precious metal used in fine jewelry that is 90% to 95% pure, largely hypoallergenic, and tarnish-resistant. It is estimated that if all the platinum in the world were poured into an Olympic swimming pool, it would be hardly be deep enough to cover your ankles, on the other hand, gold would fill more than three pools.