4.Turquoise Processing

The earliest successful treatment method was developed by Colbaugh Processing in the 1950s. Recognizing that it was wasteful to cast aside the lower-grade turquoise, the Colbaughs developed a scientific process for strengthening the softer grades of the gem. The process called stabilizing brings out the natural color of the gem, while giving it sufficient hardness and strength to survive lapidary treatment. The process is still not public knowledge, but Marty Colbaugh’s general technique is that: The turquoise has to be thoroughly dried. This is done by intense and prolonged heating It is then infused under pressure with epoxy so that the epoxy penetrates the stone. Afterwards, the turquoise is sealed in small metal containers and cooled very slowly. The entire process takes months. Sometimes, the canisters explode and entire lots are destroyed. If successful, the resulting turquoise shows a nice natural color, is easily polished and is strong enough to be worked by the lapidary. Best of all, it can be obtained at a price the lapidary can afford. If this and other processes had not come along, the supply of useful turquoise would have dried up long ago, and turquoise would never have achieved the popularity it has developed since the 1970s. People like the Colbaughs deserve a lot of credit for the continued widespread use of turquoise today.

We know that wax makes turquoise more resistant. Being relatively soft, turquoises are sensitive. As the color may pale when the stone has been worn for a long time, even high-quality stones today are treated with wax and subsequently hardened. This treatment makes the sensitive gemstone more resistant. In the trade, there are a large number of reasonably priced turquoises sealed with synthetic resin. They have a fresh color and good durability whenever, many of them are dipped in a coloring medium before being subjected to durability treatment a process that must according to the rules of the ICA, be drawn to the attention of the prospective purchaser. And there is also such a thing as a 'reconstructed turquoise', which is made from pulverized turquoise. Because of their sensitivity, turquoises are almost always subjected to treatment of one kind or another, though this may take any of a number of different forms. For this reason, turquoises which have a good natural color and are simply hardened with colorless wax or synthetic resin have a much higher value than stones whose color has been 'improved'”. So it is more advisable to purchase valuable turquoise jewellery at a jeweller's.

The natural turquoise resource is very rare so some of the most desirable materials going for a higher prices. But the increased demand could not be met through production of acceptable mine run materials. Therefore, an industry emerged the business of turquoise stabilization, reconstitution, and the manufacture of synthetic and simulated turquoise. In most instances the stabilization and reconstitution of turquoise involve the use of earthy or highly porous types of turquoise which are pressure impregnated with hot acrylic resins. The resins improve the color, hardness, and durability of the material to a point that inexpensive porous, poorly colored, or nearly colorless materials become suitable for use in jewelry. As long as the materials are represented as treated, stabilized or reconstituted, the marketplace can accept or reject the materials based on decisions that are purely business or economic.