Rhenium

Rhenium was the last stable, naturally occurring element to be discovered, found in 1925 by Walter Noddack, Ida Noddack, and Otto Berg. Named after the Rhine River in Germany, rhenium is extremely rare — it is the 77th most abundant element in Earth's crust. The Noddacks detected it using X-ray spectroscopy in platinum ore and the mineral columbite.

Rhenium has the third highest melting point of any element and is incredibly resistant to wear. Its primary use is in superalloys for jet engine turbine blades, which must withstand extreme temperatures and forces. Rhenium-containing catalysts are also used in petroleum refining to produce high-octane gasoline. Because of its rarity and demand, rhenium is one of the most expensive industrial metals.

Rhenium's symbol 'Re' is an excellent two-letter element in Spellement. It matches the start of words like 'read,' 'real,' and 'return,' fitting one of the most common English letter pairs. The 're-' prefix appears in hundreds of English words, making rhenium a word-building powerhouse.