The Gemstone Ruby (Yaqoot)
What is Ruby (Yaqoot)
A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide). Other varieties of gem-quality corundum are called sapphires. Ruby is one of the traditional cardinal gems, together with amethyst, sapphire, emerald, and diamond. The word ruby comes from ruber, Latin for red. The color of a ruby is due to the element chromium.
Some gemstones that are popularly or historically called rubies, such as the Black Prince’s Ruby in the British Imperial State Crown, are actually spinels. These were once known as “Balas rubies”.
The quality of a ruby is determined by its color, cut, and clarity, which, along with carat weight, affect its value. The brightest and most valuable shade of red called blood-red or pigeon blood, commands a large premium over other rubies of similar quality. After color follows clarity: similar to diamonds, a clear stone will command a premium, but a ruby without any needle-like rutile inclusions may indicate that the stone has been treated. Ruby is the traditional birthstone for July and is usually pinker than garnet, although some rhodolite garnets have a similar pinkish hue to most rubies. The world’s most valuable ruby to be sold at auction is the Sunrise Ruby.
Ruby, gemstone composed of transparent red corundum (q.v.), a mineral form of aluminum oxide, Al2O3. Its colour varies from deep cochineal to pale rose red, in some cases with a tinge of purple; the most valued is a pigeon-blood red. The red colour arises from the replacement of a small number of aluminum atoms by chromium atoms (1 in 5,000). High refractivity is characteristic; when cut and polished, ruby is a brilliant stone, but, because it has weak dispersion, it lacks fire. On exposure to high temperature, ruby becomes green but regains its original colour upon cooling. When subjected to radiant discharge, ruby phosphoresces with a vivid red glow.
Ruby Stone (Yaqoot) History
Symbolic of passion, protection, and prosperity, ruby gemstones have been revered since ancient times. Rubies have been particularly prized in Asian countries. Records suggest that rubies were traded along China’s North Silk Road as early as 200 BC. Chinese noblemen adorned their armor with rubies because they believed the gem would grant protection.
Burma has been a significant ruby source since at least 600 AD. Burmese rubies are still some of the most prized of all ruby gems.
After classical Burmese mines were depleted, the Mong Hsu region of Myanmar started producing rubies in the 1990s. Though these lacked the rich red hue of traditional Burmese rubies, they were treated with heat to improve saturation and transparency. Heat-treated rubies is a common practice nowadays.
Though ruby has a long history, it wasn’t recognized as a variety of corundum until 1800. Prior to that, red spinel, tourmaline, and garnet were also believed to be ruby. Even the Black Ruby, one of the famed crown jewels of England, was considered one of the largest cut rubies until determined to be spinel.
Imitation ruby dates back as far as Roman times, though it wasn’t synthesized until the early 1900s.
The red fluorescence power of ruby helped build the first working laser in 1960. Rubies—both natural and synthetic—are still used to make lasers, as well as watches and medical instruments.