A sapphire can be found in every color of the rainbow except red which is ruby. Your sapphire and diamond engagement ring is a classic in blue. Ruby is the sister stone to sapphire in the corundum family. Sapphires have a hardness of 9 out of 10 on the Mohs scale of hardness. Your sapphire and diamond engagement ring is a terrific ring for everyday wear. Just like rubies, the sapphires come from Burma or Kashmir. Those blue sapphires have the most pure blue color and are very expensive. Sapphires from other regions such as Sri Lanka, producing the Ceylon sapphire and Tanzania, Brazil, Africa and even Montana, in the United States have stunning colored sapphires. Many flock to the Montana sapphire because of its unusual natural color of blue. If you are looking for a natural sapphire in an affordable price range, a Montana sapphire is the way to go. It is good to know that most colored gemstones are either heat treated or enhanced in some way. Heat treatment and enhancement such as infusion of colorless oil, wax or resin are used to improve color and clarity and is considered a common practice. You should assume a sapphire is heat treated unless otherwise disclosed. Color Color is the most important factor in the selection of the sapphire for your engagement ring. You want to look for the hue or color, the intensity of the saturation and also the tone, the darkness or lightness of the saturation of color. Clarity Clarity, cut and carat weight are also important factors. Most colored gemstones have some inclusions so you need not be thrown off by it. Inclusions the fingerprints of your stone and are often minimized through the use of clarity enhancement. Cut Cut has to do not only with the shape of the stone but more importantly with the function of the cut, which is to bring out the gemstone intrinsic beauty. Carat Weight Carat weight has to do with the weight of the stone, for instance, one carat or the diameter of the stone, for example 6 millimeter. To select the perfect sapphire for your engagement ring many things need to be taken into consideration, enhancements, color, most importantly, clarity, cut and carat weight. All of these things together affect the price you will ultimately pay for your special sapphire engagement ring.