Maria Callas had a grand collection of jewelry and was known for her love of Van Cleef & Arpels. In addition to the Cinq feuilles clip (1967) made of platinum and set with six Burmese rubies totaling 15.77 carats, as well as 16.35 carats of diamonds, she also wore a ruby and diamond ribbon necklace and a ruby and diamond Van Cleef & Arpels brooch.
Unfortunately, I don’t have any more information about the specific pieces of jewelry that Maria Callas wore.