These were magic earrings in the shape of small stars, made for women. In addition to having a protective effect, they also have a magical effect that restores the wearer's physical health. They are very valuable and are not sold on the open market, but were only occasionally dropped by the Hell Unicorns that reside in Neclord's Castle.
Incidentally, for some reason, noble types such as Milich Oppenheimer, Simone Verdricci, and Vincent de Boule were able to equip them. Sheena also wore a pair, perhaps passed down from his mother, Eileen, who wore a pair during the Gate Rune War.
