Considered in the ancient East to be the luckiest of all gems, the ruby is said to confer upon its owner protection from all misfortune either manmade or natural. Like the sapphire, the ruby is a member of the corundum family, an aluminum oxide that owes its bright red color to the trace presence of chromium. The major sources for this mineral both in antiquity and today is the Orient, especially Burma, Thailand and India. On a carat for carat basis, the ruby is generally the most expensive of all precious stones. The most prized hue for the gem is called "pigeon's blood", a deep red touched with violet. A necklace of these stones is said to have been given by Alexander the Great to the Queen Mother of Persia. However, because of its Eastern origins, the ruby was little known to the classical cultures of the West. In the East, especially India, the ruby was much sought after. Sanskrit writings refer to it as the "king of gems". Its red color associated it medicinally with diseases of the blood, and it was especially valued to ward off pestilence, to staunch bleeding, as well as cure diseases of the stomach. In Eastern belief, it also promoted peace and prosperity for its owner, and granted him invulnerability from all evil.