How Are Sapphires Obtained?

Identifying Sapphires

Sapphires come from a mineral called corundum which is categorized as an aluminum oxide. Sapphires are found in a number of colors and this is due to the combination of trace elements found mixed with the corundum. Chromium, iron and titanium in varying amounts can give the stone its colors of blue, yellow, purple, green and pink. Large amounts of chromium create a deep red color in the stone. This color is referred to as a ruby and is categorized as a separate from other sapphires. Sapphires have been part of adornment and jewelry for centuries. Its place on the mineral hardness scale is a nine, 10 being the hardest type of mineral. Its hardness allows for its use in manufacturing and is found in blue LEDs, infrared optical applications, watch crystals and in the semiconductor industry.

How Sapphires Are Made

Sapphires are found naturally but they can also be manufactured or grown. The method used to grow sapphires is called the Czochralski process. Manufacturing begins with a seed crystal of sapphire from which more are grown. The seed is dipped down into a bowl of hot melted alumina and slowly removed at a pace of 1 to 100 mm in an hour. The alumina that is on the end of the seed crystallizes and creates the long carrot like shapes called boules (a synthetically formed mass) made of the same composition of a sapphire. The abundance of these synthetic sapphires allow for their industrial use and they are bought and sold in large volume in the marketplace. Natural sapphires can be "treated" to produce a deeper color and better clarity. A common practice is to heat the natural stone to temperatures of 500 to 1800 degrees C. This is so common that an unheated natural stone is hard to come by and when one is found and sold it will have documentation from laboratory testing that states there has been no heat treatment to the stone.

Where Sapphires Are Found

Natural sapphires are found in specific areas of the world. Their selling price is figured by the stones characteristic--color, clarity, cut and size--as well as where they are geographically found. Mined from river beds, from underground locations and also directly from the earth's surface, sources for the best sapphires are found in Kashmir, Myanmar, Sri Lanka and Madagascar. Natural sapphires are also found in China, Thailand, Africa, Australia, Pakistan, Afghanistan and the United States. An intense blue variety of sapphire is found near the area of Utica, Montana. Both rubies and sapphires are usually found together with one or the other predominate in a particular location.