Rhodium

Rhodium is the most expensive precious metal in the world — at times costing more than gold, platinum, or palladium. Discovered in 1803 by William Hyde Wollaston in crude platinum ore, rhodium gets its name from the Greek 'rhodon,' meaning rose, because of the rose-red color of some of its compounds.

About 80% of the world's rhodium goes into catalytic converters in cars, where it helps convert toxic exhaust gases into less harmful ones. Rhodium is also used to plate white gold and sterling silver jewelry, giving them a brilliant, tarnish-resistant finish. It is so rare that the entire world's annual production would fit in a room — only about 30 tonnes are mined per year.

Rhodium's symbol 'Rh' is a distinctive two-letter element in Spellement. It can help spell words that start with 'rh' like 'rhythm' and 'rhyme,' matching an uncommon but recognizable English letter pair. Partial emphasis also allows using 'r' or 'h' individually for flexible word building.