Rhodium is a beautiful white metal. Its luster & reflectivity make it particularly useful in jewelry, where a thin layer applied to the underlying metal can make it shine like silver.
It is corrosion resistant, unaffected by air & water up to 1,112oF, and impervious to attack by acids.
British chemist William Hyde Wollaston discovered this element in 1803 by dissolving platinum ore in acid, then precipitating out platinum & palladium, leaving a rose-colored solid.
He extracted [rhodium chloride] crystals, which reduced to the resulting metal when heated with hydrogen.
The element was named after the Greek word rhodon (rose-colored).
Rhodium is 1,000 times rarer than gold. It has been used to bestow great honors. In 1979 the Guinness Book of World Records presented Paul McCartney with a rhodium-plated disk to celebrate his achievement as history's best-selling recording artist & songwriter.
Rhodium is mainly used in vehicles' catalytic converters.
With its high reflectivity, rhodium is used to coat optical fibers, mirrors, & the reflectors of car headlights.
Rhodium can absorb oxygen from the atmosphere without becoming oxidized itself. When the element melts at 3,567oF it captures oxygen; then releases it when the molten metal solidifies.
Rhodium is now about $28K/oz, compared to around $2K a couple of years ago. If only I had a time machine.