"The Roman pearl craze began after Pompey the Great’s military campaigns in Asia Minor and Armenia (66-63 B.C.). During Pompey’s triumphal return to Rome in 61 B.C., his procession included 33 crowns encrusted with pearls, a pearl-decorated shrine, and a portrait of the general made entirely of pearls."

https://www.nationalgeographic.com/history/magazine/2019/03-04/roman-republics-captivation-with-pearls