Ruby is the July birthstone and one of the most valuable gems. The name comes from the Latin word ruber, which means "red" - the colour of love and passion.
Ruby was known as the "king of precious stones" in ancient India due to its scarcity, hardness (second only to diamond), beauty, and seemingly mystical powers. Ruby, long associated with the life force blood, was a symbol of power and youthful energy in Indian jewellery. Some believed this July birthstone could foretell misfortune or danger, while others claimed it could cure inflammatory diseases and soothe anger. Burmese warriors believed it made them invincible in battle. The mediaeval Europeans believed that rubies bestowed health, wisdom, wealth, and love success.
Rubies are made of corundum, the same stone as sapphires, and chromium is the trace element that gives rubies their signature red colour. Rubies have a Mohs hardness rating of 9 and are therefore suitable for everyday wear jewellery.
Cancer is the fourth sign of the zodiac, governing the time period from about June 22 to about July 22. Its depiction as a crab (or lobster or crayfish) alludes to the crab in Greek mythology that pinched Heracles while he was fighting the Lernaean hydra.