Color range: all shades of red to light pink 

Among the multitude of legends and strange beliefs of ancient times, it was thought that the wearer of a ruby was blessed with health, wealth, wisdom, and outstanding success in affairs of the heart.  Furthermore, the wearer acquired the ability to live in peace with his enemies.   In some places ruby was even thought to confer invulnerability.  Red stones including rubies were thought to cure bleedings. A stone which turned darker was thought to warn its owner of coming misfortunes, illness, or death.

All colors of corundum except red are known as sapphires, which has created controversy about where ruby ends and sapphire begins, particularly in pink shades of corundum.   The close relationship of ruby and sapphire has been known since the beginning of the 19th century.  Up to that time, red garnets or spinels were also thought to be rubies – and due to this misclassification the so-called "Black Prince's Ruby" as well as the "Timor Ruby" decorating the British Crown Jewels are probably actually not rubies at all, but spinels.

Eastern legends believe that rubies contain the spark of life "a deep drop of the heart's blood of Mother Earth."  Some ancient Orientals believed that the ruby is self-luminous and called it "glowing stone" or "lamp stone."  It is believed that the Emperor of China used a ruby to light his chamber.  Hindu priests believed that the homes of the gods were lighted by emeralds and rubies.

Greek legends also speak of ruby.  It was said that a female stork repaid Heraclea for her kindness by bringing her a ruby so bright that it illuminated her room at night.

Ancient Hindus, Burmese, and Ceylonese believed that rubies ripen with age.  The believed that sapphires were unripe rubies and that inclusions in stones meant that they were overripe.