Of the 3 precious colored gemstones, which include ruby, sapphire and emerald, ruby and sapphire are actually considered to be the same material and are part of a gemstone family called corundum. Of all of the varieties of color in sapphire, which can be found as colorless, pink, purple, green, orange, yellow, padparadscha (orangy pink) and most popularly, blue sapphire, the red variation of sapphire is called Ruby.
Rubies can be found in a number of locations around the world, and the country of origin can play a large role in the value of a ruby. Today most people consider Burmese rubies to be the most desirable, while rubies are also found around the world in places such as Thailand, Tanzania, Sri Lank, Madagascar, the United States, Brazil and Pakistan.
Ruby is a very hard material and ranks at a number 9 on the Mohs Scale of Mineral Hardness, where diamond ranks as the hardest gemstone at 10 on the scale.
Ruby colors incorporate many hues of secondary colors as well including, purple, pink, orange and brown, while the more pure the red, the more valuable the ruby.
When buying a ruby, one should take into consideration the color as the most important factor. Clarity is secondary to color in rubies to a certain degree, but if the ruby is full of unsightly inclusions it can drastically take away from the value and desirability.