Sapphires and rubies are composed of the same material, corundum. The difference is that rubies are a specific red color, and sapphires can be all other colors, white, black, pink, orange, yellow, green, blue, and purple! You may be asking, if they're made of the same thing, how are they different colors? Gemstones get their color from what we like to call, trace elements. In order for a sapphire to become blue, it needs trace elements of iron and titanium. In order to produce a ruby red color, the trace element, chromium needs to be present.
Sapphires and rubies are a great way to add color to a piece of jewelry. They're typically very vivid in color and are a 9 on the Moh's hardness scale, which is the hardest stone next to a diamond.
Most sapphires are mined in Africa and southern Asian countries, however there is a sapphire mine, here, in the United States! The area of Yogo Gulch, Montana is known to produce beautiful sapphires.
When purchasing a sapphire or ruby, ask your salesperson about whether or not the stone has been treated. A good number or sapphires and rubies are heat treated to intensify the color. This is important to know because heat during a routine repair can change the color of the gemstone. Although some may see a treated gemstone as a bad thing, it typically will make the stone more beautiful and actually have a lower cost than a natural color equivalent.
If sapphires or rubies are out of your price range, consider a lab created sapphire. You won't have to worry about inclusions and the pricing is typically around $350 per carat.