In modern Hebrew the word for "pearl" is "pninah". This is the same as the biblical name
Peninnah mentioned in 1.
Samuel 1. In the bible the word "pninah" translates "coral" as well as "pearl" (see Lamentations 4,7).
A second word for "pearl" in modern Hebrew is "margalith", which is the eqivalent to the Greek "margarites". I don't know, whether Margalith has been used as a name among Jews.