In Sanskrit, ruby is Ratnaraj, meaning the king of gems.
Red is the color of our most intense emotions—love and anger, passion and fury. It’s associated with objects of power and desire—like fast cars and red roses. Early cultures treasured rubies for their similarity to the redness of the blood that flowed through their veins and believed that rubies held the power of life.
The most renowned rubies, like those from Myanmar, the Himalayas, and northern Vietnam, typically form in marble. They’re found in layers that are distributed irregularly within the surrounding marble. Marble forms as part of the metamorphic (rock-altering) process, when heat and pressure from mountain formations act on existing limestone deposits.
The name ruby comes from the Latin word rubber, which means “red.” The glowing red of ruby suggested an inextinguishable flame burning in the stone, even shining through clothing and able to boil water.
Color is the most significant factor affecting a ruby’s value: Fine gems are pure, vibrant red to slightly purplish red.
In addition, rubies found in marble typically fluoresce red under ultraviolet light—even the ultraviolet light in sunlight. Fluorescence can make a ruby’s color even more intense and increase its value.
Chemical composition: Al2O3
Refractive index: 1.762 to 1.770
Birefringence: 0.008 to 0.010
Specific gravity: 4.00( /- 0.05)
Mohs Hardness: 9 on the Mohs scale
Sources: Afghanistan, Kenya, Madagascar, Myanmar(Burma), Sri Lanka, Tanzania, and Vietnam
Stability: Corundum is stable under normal wearing conditions, which means it’s resistant to the effects of heat, light, and common chemicals. The boric acid powder will etch the surface of even untreated stones. Fracture-filled, cavity-filled, and dyed stones can be damaged by even mild acids like lemon juice.
Cleaning: Warm soapy water is always safe. Ultrasonic and steam cleaners are usually safe for untreated, heat-treated, and lattice diffusion-treated stones. Fracture-filled, cavity-filled, or dyed material should only be cleaned with a damp cloth.
Treatment and durability considerations: Untreated ruby and even heat-treated ruby are very durable. Stones that have undergone lattice diffusion treatment have varying degrees of treated-color penetration. In some stones, the treated color penetrates the entire stone, while others have very shallow treated-color penetration. For stones with shallow color penetration, surface damage or re-cutting can remove color. Today’s fracture-filled stones have surface-reaching fractures filled primarily with high-lead content glass. There are large numbers of these treated rubies in the market and they require greater care than untreated, heat-treated, or lattice diffusion-treated ruby. The glass can be damaged through contact with a variety of chemicals. Even relatively mild substances like lemon juice can cause changes in the high-lead content glass.