The ruby is a red gemstone that can vary from a light pink to a deep blood red. It is a variety of the mineral corundum or aluminium oxide. The red color or luster is caused mainly by chromium.

The name ruby originates from ruber, the Latin for red. Natural rubies are exceptionally rare, but synthetic rubies (sometimes called created ruby) can be manufactured fairly cheaply. Other varieties of gem-quality corundum are called sapphires. See All About Sapphires. Ruby is considered one of the four major precious stones, together with the sapphire, the emerald and the diamond.

Rubies are mined around the world in Africa, Asia, Australia, Greenland, Madagascar and North Carolina. They are most often found in Myanmar (Burma), Sri Lanka, Kenya, Madagascar, and Cambodia, but have also been found in the U.S. states of Montana, North Carolina and South Carolina. The Mogok Valley in Upper Myanmar had produced some of the finest rubies in recent years this has dropped off and a very few good rubies have been found there.

The unique color in Myanmar (Burmese) rubies is described as “pigeon’s blood”. They are known in the trade as “Mogok” rubies. In central Myanmar the area of Mong Hsu also produces rubies. The latest ruby deposit to be found in Myanmar is situated in Nam Ya. In 2002 rubies were found in the Waseges River area of Kenya. Sometimes spinels are found along with rubies in the same rocks and are mistaken for rubies. However, fine red spinels will only approach the average ruby in value.

The very best rubies and most expensive rubies come from Burma, paler ones from Sri Lanka. Rubies from Thailand are yellower. Smaller and less valuable rubies have been found in North Carolina. A big, nearly perfect ruby from Burma could be as valuable as a diamond the same size if not more.

Rubies have a hardness of 9.0 on the Mohs scale of mineral hardness. Among the natural gems only diamond is harder.

All natural rubies have imperfections in them, including color impurities and inclusions of rutile needles known as “silk”. Gemologists use the needle inclusions found in natural rubies to distinguish them from synthetics, stimulants, or substitutes. Usually the rough stone is heated before cutting. Almost all rubies today are treated in some form (of which heat treatment is the most common practice), and rubies which are completely untreated and still of excellent quality command a large premium. In general we can list the following types of improvements: color alteration, improving transparency by dissolving Rutile inclusions, healing of fractures (cracks) or even completely filling them. See Treatments below.

Prices of rubies are primarily determined by color (the brightest and best “red” called Pigeon Blood Red, command a huge 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 will indicate the stone has been treated one way or another. Cut and Carat also determine the price more or less to a similar extent as does the luster or clarity.

It is important, to ensure you are getting the right rubies, to have a ruby valued properly. An appraisal from a qualified Gemological laboratory is well worth the effort and expense for the larger rubies.

This entry was posted on Sunday, April 29th, 2007 at 11:11 am