Heat treatment – methods for handling stones

Heat treatment method

Many precious stones have been treated (many are called “enhance stone age”) by various methods to improve their color and transparency. Today, some methods are widely accepted in the trading of diamonds, while some other methods are no longer allowed. The methods that are approved are ways that will change the color of the stone permanently, methods that do not meet this factor will be likely unacceptable.

The concept

Ethical and reputable gem traders always provide a complete record of the rock, including the methods used to treat the stone. Our view is that the details of each stone need to made available to the customer so that they know exactly what they are paying. So, in this article, we provide the information so that you can learn the standard processing methods, as well as recent innovations. A lot of colored gemstones have been treated, which is a fact, and it is perfectly legal if the applied treatments are fully disclosed in the record of the stone

Heat treatment

Heat treatment method

Heat Treatment Method

Some centuries ago, people accidentally discovered the magic effect of heating the rocks. At high temperatures, such as the hot temperature of coal, can make a pale looking stone change color spectacularly. If this technique is not fortunate to discover, the market will have very few of the stones of right color that are reasonably priced.

Heat treatment is considered a natural strengthening process because it is a continuation of the process that occurred in the earth’s crust when the stone was formed. The stone is heated to a very high temperature (about 1600 degrees Celsius) leading to the removal of capsules, chemical elements, impurities that modify and change the color of the stone. The color changes here may be one of the two results, whether the stone will be brighter, darker or have a more attractive color or a completely different color. An example of the heat treatment is the decomposition of rutile fibers in blue sapphires, which improves the quality of the stone both in color and color. Clarity Heat treatment of stones is a permanent treatment and cannot be reversed.

Another example is Ruby, which is usually heat treated. Only the most valuable and expensive ruby stones own the best colors without heat treatment. The heat treatment process for rubies is done by heating the stone almost to its melting point, allowing the aluminum oxide molecules in the rock to change, creating a new crystalline structure. This also makes the chromium atoms in the stone combine with other atoms, creating better red. Likewise, this technique can be applied to a type of jade called milk gouda sapphires that turn blue, one of the most famous jade jams in the market today.