This word refers to the Sardian stone, a gemstone named after Sardis in Asia Minor. Ancient sources distinguished two varieties: the transparent red 'female' stone (our carnelian) and the transparent brown 'male' stone (our sardine). Greeks and Romans prized these stones for seals and ornaments. The stone appears in biblical descriptions of priestly garments and apocalyptic visions, where its deep red color carried symbolic weight. Later Greek writers used various forms like σάρδιος, σάρδινος, and σαρδόνιον to refer to this prized material, which decorated both sacred and secular objects throughout antiquity.