Which precious metal was discovered in 1844 by Karl Ernst Claus?

Which precious metal was discovered in 1844 by Karl Ernst Claus? The answer is ruthenium.

Russian chemist Karl Ernst Claus identified ruthenium in 1844 while studying platinum-ore samples from the Ural Mountains. He isolated the element, measured its atomic weight, and investigated its chemical properties. Claus named it after Ruthenia, the Latin name associated with Russia.

Ruthenium is a chemical element with the symbol Ru and atomic number 44. It belongs to the platinum-group metals, alongside platinum, palladium, rhodium, iridium, and osmium. These metals are often grouped together because they are scarce, corrosion-resistant, and chemically useful.

A common mix-up is confusing ruthenium with rhodium or iridium, which Claus also studied during his work with platinum ores. Ruthenium is used in catalysts, electrical contacts, chip resistors, and some hard-wearing metal alloys.