Ruby
(July Birthstone)

Ruby from Africa 
 

Scientific:
Ruby is the red variety of corundum, the second hardest natural mineral known to mankind. Gem corundum of any color is referred to as sapphire with a preceding color designation if the color is any other than blue. Blue corundum is simply called sapphire. There are two other color varieties of corundum that have specific names, the pinkish-red to red ruby and the orange-ish-pink padparadscha. 

The famous pinkish-red to red ruby owes its color to chromium (Cr3+) impurities, and the color of the rare orange-ish-pink padparadscha sapphire is from both iron and chromium impurities. 

The name corundum was derived either from the Sanskrit kurivinda or from the Indian name for corundum kauruntaka. Ruby is from the Latin word ruber meaning red. 

Oriented rutile crystal inclusions cause a six-rayed-star light effect (called asterism) to form the popular Star Ruby.

Imperfections and impurities may be removed by controlled heating of the gemstones. Some rubies have fissures or surface breaks that are filled with a glass-like byproduct of the heating process. 

The brightest red and thus most valuable rubies are usually from Burma. Violet red, sometimes quite dark, rubies come principally from Thailand. This is today's main source of rubies. Small quantities of rubies also come from Sri Lanka, Cambodia, Pakistan, India, and even Tanzania. Rubies have long been cherished among the world's most beautiful and valuable gems. The hardest mineral after diamond, and because of its brittleness, requires care when cutting. There are so few unflawed Rubies in sizes larger than 5 carats, that anything larger is more valuable than even a Diamond of equal quality and size.

Because of its high specific gravity rubies that come from alluvial sources such as Sri Lanka and Burma are collected in a deep cone-like separator. Gravel and water are placed in the cone and the cone is rotated. Minerals with low specific gravity such as quartz, mica and calcite wash out of the cone as it is rotated. The miner will finish with an aggregate of higher specific gravity minerals near the vertex of the cone. If the miner is fortunate, a few of these stones might prove to be rubies. Red spinel may also be included in these heavy minerals but they are easily separated from ruby by both physical and optical properties.

History:
Ruby has been the world's most valued gemstone for thousands of years. In the ancient language of Sanskrit, ruby is called "ratnaraj" or "king of precious stones", and ratnanayaka or "leader of precious stones".

The ruby mines of Myanmar are older than history. Stone Age and Bronze Age mining tools have been found in the mining area of Mogok.

The gold coronation ring of the English kings contains a large, tablet-cut ruby on which the figure of St. George's cross is engraved. Around the ruby are set 26 diamonds. Rubies are generously represented in crowns and scepters in the royal jewels of many nations. 

Ruby was said to preserve health and give invulnerability from wounds, and to guarantee that one's status and possessions would never be taken. The wearing of a ruby was said to signify manhood, nobility and valor in a man, and pride & passion in a woman. 

Ground rubies were used as a remedy for stomach ailments.

Ruby has also been connected to dragons. Legends tell of dragons guarding Ruby and Emerald mines and others of dragons with brilliant Rubies in their heads illuminating the countryside!