Noun
A rare metallic element of the platinum group, found native as an alloy in platinum ore, and in iridosmine. It is a hard, infusible, bluish or grayish white metal, and the heaviest substance known. Its tetroxide is used in histological experiments to stain tissues. Symbol Os. Atomic weight 191.1. Specific gravity 22.477.
Source: Webster's dictionaryAfter it is dissolved, osmium is separated from the other platinum group metals by distillation or extraction with organic solvents of the volatile osmium tetroxide. citation The first method is similar to the procedure used by Tennant and Wollaston. Source: Internet
Because osmium atoms are extremely electron-dense, osmium staining greatly enhances image contrast in transmission electron microscopy (TEM) studies of biological materials. Source: Internet
Blackening reveals oxidation due to irradiation by oxygen atoms. citation citation Precautions Finely divided metallic osmium is pyrophoric and reacts with oxygen at room temperature, forming volatile osmium tetroxide. Source: Internet
At the time, a group at BASF led by Carl Bosch bought most of the world's supply of osmium to use as a catalyst. Source: Internet
For example, the PGMs mined in South Africa contain on average 11% ruthenium while the PGMs mined in the former USSR contain only 2% (1992). citation citation Ruthenium, osmium, and iridium are considered the minor platinum group metals. Source: Internet
For instance, osmium -iridium alloys could be investigated if platinum's propensity to absorb hydrogen (due to catalysis of VOCs and hydrocarbon-based cleaning solvents) and atmospheric mercury proved to be sources of instability. Source: Internet