Tar-Elestirnë

Erendis, the Queen of Númenor, caused the diamond which Tar-Aldarion brought to her from Middle-earth "to be set as a star in a silver fillet and at her asking he bound it on her forehead."

For this reason she was known as Tar-Elestirnë, the Lady of the Star-brow and thus came, it is said, the manner of the Kings and Queens afterward to wear as a star a white jewel upon the brow, and they had no crown".

See also Aldarion and Erendis