Sapphires are a beautiful stone that is made of an aluminum oxide composition. They can be blue, white or almost any other color. They can even be multicolored. In 2010, sapphires are found in nature, and they can be created in the lab.
What is a Sapphire?
A sapphire is a corundum of aluminum oxide which can contain other minerals. It is these other minerals that give the sapphire its color. The distinctive blue color of many sapphires comes from titanium or iron caught in the crystalline structure of the gem. Other colors are the result of other metallic elements incorporated into the composition of the sapphire.
Where Are Sapphires Mined?
Sapphires are found in many types of rock deposits. They can be located in igneous rock, metamorphic rock or as secondary deposits in conglomerate rock. Geographically they are mined in many parts of the world including Myanmar, China, Thailand and Sri Lanka in Asia; Afghanistan, India and Pakistan in the Middle East; Kenya and Tanzania in Africa; Madagascar in the Indian Ocean; and in Australia. They also are mined in the United States, in places like Washington state, Montana and North Carolina.
How Sapphires Form Naturally
Sapphires are formed deep below the Earth's crust. They are brought to or near the surface by volcanic vents containing hot lava. If they are in the vent long enough, the temperature is hot enough, and the pressure is strong enough, a sapphire is formed.
Once the sapphire is mined, it can be heat-treated to bring out different colors. It was originally the people of Thailand who found that by putting sapphires in a very hot furnace, the color was improved and impurities were removed. This process is still considered to produce natural sapphires.
Into the Lab
Since science is able to determine the chemical makeup of sapphire, it also allows you to produce these gems in the laboratory. In 2010, you can find artificial sapphires made up of exactly the same substances found in natural stones. Aluminum oxide is mixed with another metallic material and then is crushed into a powder. This mixture is then heated to nearly 200 degrees Fahrenheit, and a sapphire is formed.
Differences Between Natural and Artificial Sapphires
Although the composition of natural and lab-made sapphires is exactly the same, an expert can tell the difference between the two. In the natural sapphire there are cavities or bubbles which always have an irregular form. You will find that those in the lab-made gems are perfectly round.
The Value is Different
Both lab sapphires and natural sapphires have exactly the same chemical composition and most of the same properties. Nonetheless, on the world market, the artificial sapphire is worth considerably less than the natural one. This is true even though you will have to find an expert to tell you which is which.