Like many gems, rubies are known by several names. One of its earliest titles was ratnaraj, which is Sanskrit for “king of gems.” Another early name was carbuncle. At a time when gems were classified by colors only, carbuncle was the name given to all red gems, including rubies. The current word, ruby, is derived from the Latin word for red.
Rubies have always been among the most highly valued of all gemstones. Fine rubies are transparent, with an inner glow. Ancient peoples attributed the glow to an eternal flame, or the spark of life. They believed that rubies carried the power of the sun within them. They wore rubies to attract energy, wealth and power to themselves.
Rubies are also associated with passion and success in love. Many also believed in the protective powers of rubies, thinking that wearing a ruby would keep them safe from negativity (including witches) and repulse all foes. Rather than wearing a ruby and risk losing its protective powers, some individuals, especially soldiers, had their gems surgically implanted under their skin.
Rubies today are valuable due to their rarity. The best of them sell for thousands of dollars a carat. Color is the most prized characteristic. Faceted stones are often cut to display the best color, even if that means significantly reducing the number of carats in the finished gem.
Ruby is the transparent red variety of corundum, nature’s second-hardest mineral. (Only diamond is harder.) Not only are rubies hard, they’re also very durable, making them an excellent choice for all kinds of jewelry. Like most minerals in their pure state, corundum is colorless. Various chemical impurities create different colors. Red corundum is ruby; all other colors are called sapphires.
The red comes from minute amounts of chromium. Colors vary from pale rose to almost black. “Pigeon-blood red”, a deep purplish-red, is the most prized shade.
Star rubies contain another impurity, usually rutile crystals, which create the illusion of a 6-pointed star on the gem’s surface. Traditionally mined in Myanmar (Burma) since prehistoric times, rubies marketed today come mostly from India, Sri Lanka and Thailand. Virtually all rubies are heat-treated to enhance the color.
Balas ruby is spinel; Bohemian ruby is rose quartz; Siberian ruby is tourmaline; and Cape ruby is garnet. The Black Prince’s Ruby in the British Crown Jewels is spinel. Synthetic ruby, made since the early 1900s, cannot be distinguished from real ruby with the naked eye.
Much of the synthetic ruby manufactured, however, is used in watches and precision instruments, including lasers, rather than for jewelry.