about Osmium » Occurrence
The information one can find about osmium varies from source to source, especially regarding the incidence of osmium in the earth’s crust. Common figures indicate that osmium’s occurrence in the earth’s crust is a mere 0.001 ppm, which would be extremely rare. However, these numbers are extrapolated, and for this reason the rarer a metal is, the less accurate they tend to be. Osmium is usually associated with the other platinum metals ruthenium, rhodium, iridium, palladium, and platinum. For this reason, sample calculations can be made that define the amounts of osmium somewhat better.
The Osmium World Council publishes the latest figures in its annual report. These figures can be found at www.osmium-world-council.com. Conclusive figures for osmium’s occurrence in the earth’s crust and in circulation are difficult to calculate because both China and Russia treat such information as state secrets and do not divulge them. The information provided by the mines with which osmium extraction is associated can also be quite speculative. Therefore, the figures quoted are seldom accurate.
Osmium deposits are divided into resources and reserves. In other words, the deposits are defined by how much osmium is predicted to be contained within a mine, and how much osmium has been confirmed to be present. However, the presence of osmium in a mine does not guarantee that it will be separated from the ores once extracted. If the occurrence of osmium in the extracted ores is too low, extraction is not economically viable, and the osmium is left in the remaining metal as trace amounts of impurity. For thousands of tons of ore, there are often only a few grams of raw osmium. The challenge of the osmium market is the purification required for osmium to be crystallizable. Once crystallized, however, osmium is pure up to a tune of 9N (99.99999995%) and is fit for use as a tangible asset or an addition to jewelry and accessories.
Osmium occurs naturally in thin platelets, but also bound as selenide, sulfide or telluride. In the process of separation from other metals, it is usually lost in the flue gas under the oxygen supply in the process of purification and is released into the atmosphere. These quantities are irretrievably lost, although they are included in the reserves at the deposits. As a result, osmium is the rarest non-radioactive metal in the world.
In general, there are various deposits of osmium, which are divided into primary and secondary deposits. Primary deposits are distributed internationally and contain copper as the main metal, as well as nickel and occasionally chromium and iron. Very small quantities of platinum metals are bound here. However, this does not mean that they are always extracted, and in the process of separating the industrial metals they are often not separated because of their small proportions. Isolated deposits of osmium ore do not exist. Osmium deposits originate from the rhenium decay series, are associated with the platinum metals in mines, or originate from the prehistoric impacts of objects from space in the early time of the earth.
In addition to the known ores of primary deposits, there are secondary, so-called “placer deposits” in which osmium and other platinum metals occur in trace amounts. The metals have been washed out by water flow have been deposited in placer deposits such as gold due to their density. Natural alloys osmiridium and iridosmium can be found here.
The most important deposits are the platinum metal-rich nickel ores in Canada (Sudbury, Ontario), Russia (Ural) and South Africa (Witwatersrand). Secondary deposits make up a less significant fraction of total osmium deposits, but can be found geographically in the Urals, throughout South America, throughout Africa, and in Indonesia.
