Sapphires are a type of precious stones that fall under the variety of a mineral known as "corundum", which is an aluminum oxide. In order for it to be considered a sapphire, it should be blue, yellow, pink, orange or green in color. If it occurs in the color red, then it is a ruby. Most gem quality sapphires will be blue in color. The origin of the word sapphire comes from the Greek word "sappheiros". The main thing to know about sapphires is that they can either be natural or artificially created in crystal boules. Sapphires are known for their incredible hardness, which make them useful in industrial applications such as infrared optical components, watch crystals, rugged windows and in the semi-conductor industry. Sapphires also occur as colorless stones as well as grey and black gemstones. There are a number of factors that influence the cost of a sapphire. They are color, clarity, carat, quality and place of origin. The places in which sapphires are most commonly found are in Australia, Sri Lanka, Thailand, East Africa and the United States. Because of their commonality, sapphire and ruby are found in the same place, although one will be more common than the other, depending on the mineral deposits of a particular mine.

Some gemstones including sapphires are graded according to their hue, saturation and tone. Hue means the color of the stone. Saturation means the brightness of the color and tone is the light or darkness of the color. Blue sapphires are judged by the clarity of their main hue. The secondary hues found in blue sapphires are violet, green and purple. The finest quality sapphire gemstones will not have more than 15 percent violet or purple. If the stone has a green hue to it, then it is considered to be of lower quality. Earlier sapphires of different colors were mentioned, of these pink and pink-orange colored sapphires are quite popular and if the quality of the stone is good it can fetch very high prices. The reason why some sapphires get pink as their primary color is because of the presence of the mineral chromium. If the stone has a deep pink-orange color it can be worth even more than a blue sapphire. These pink-orange stones are also called by the name "Padparadscha" which has its roots in the Sri Lankan language meaning lotus blossom. There is yet another type of very rare sapphire known as color change sapphire. What is unique about this stone is that it will show different colors in different types of light. This type of stone is mostly mined from the African country Tanzania.