Opal comes from the Sanskrit upala, meaning "precious stone" — the iridescent gem that shifts colour with the light. October's birthstone.
Opal peaked in the U.S. at #81 in 1911 and faded. It is returning rapidly in the 2020s as part of the broader return of gem names. Today it sits in the U.S. top 500 and is climbing fast.
Opal reduces to four — the number of shifting steady beauty.