History and Mythology*:
The constellation Libra is said to represent the Titan Themis; the Greek goddess of Law. Themis was the law of nature and was even tempered and just. Themis was not blind but was prophetic and the first oracle at Delphi.
Although Libra is the newest sign in the zodiac (having previously been part of both Virgo [as scales] and Scorpio [as claws]), many astrologers regard it as the most desirable since it represents the harvest and the high point of the year.
Characteristics of a Libra*:
diplomatic, cooperative, impartial, idealistic, peace loving, graceful, refined, gentle, sensitive to others, kind
*Note: Information on the history and mythology of Libra was taken from Wikipedia articles.