A Sign of the Zodiac

Libra is the seventh sign, a cardinal air sign ruled by Venus, and the only zodiac sign whose emblem is an inanimate object, the Scales; its opening degree marks the northern autumnal equinox. Libra is also the youngest of the twelve signs to be individuated as its own figure. To Hellenistic Greek astrologers these same stars had long been counted as the Claws, the pincers of the neighbouring Scorpion, and it was Roman tradition that recast them as an independent balance, a change commemorated to this day in the names of Libra's two brightest stars, Zubenelgenubi and Zubeneschamali, which still carry the Arabic word for claw as a fossil of the older reading passed down through medieval Arabic astronomy.

The written glyph that marks Libra on a chart belongs to the same layer of notation as the other signs, first attested in the Greek horoscope papyri of Roman Egypt catalogued by Otto Neugebauer and Henry Van Hoesen, and copied through Byzantine manuscripts across the medieval centuries. Libra's Unicode codepoint, U+264E, sits within the twelve consecutive zodiac symbols placed in the Miscellaneous Symbols block, a range of two hundred fifty-six codepoints, when it was introduced in version 1.1 in 1993.