Ginsburg was a huge opera fan, and this collar is a copy of one worn by Placido Domingo. It was from a production of Stiffelio at the Metropolitan Opera, and when Ginsburg admired it, the Met gave it to her. Ginsburg protested that the performers would need it for the following night's production, but the Met told Ginsburg they would get another one.

(from "Portraits of Ruth Bader Ginsburg's Favorite Collars and the Stories Behind Them," by Tessa Berenson, TIME, 24 November 2020)