The most common optimization treatment methods for sapphire are heat treatment and thermal diffusion treatment, as well as dyeing, crack filling, and irradiation.
The dyeing method is mainly to dip sapphire with light color and cracks into blue with dye;
The crack filling method is to fill the sapphire with more cracks in the cracks of the sapphire with glue; the irradiation method is mainly used to process the corundum into golden yellow The sapphire; the heat treatment method is to oxidize or reduce the sapphire at a higher temperature to produce the desired color. Most of the sapphires on the market have undergone heat treatment. Because this method has been around for a long time, and the color does not change after treatment, it has been widely accepted by people and is called optimization. Therefore, it is not necessary to explain the name labeling.
Gems are the most beautiful and precious kind of rocks. They have bright colors, crystal texture, brilliant luster, hard and durable, and they are rare.
They are natural mineral crystals that can be used to make jewelry, such as diamonds, crystals, emeralds, rubies, sapphires, and golden emeralds (allex, cat’s eye), Etc.; there are also a few natural single mineral aggregates, such as agate and opal. There are also a few organic materials, such as amber, pearl, coral, coral, and ivory, which are also included in the broad sense of gems.
1. The heat treatment method has the following effects on sapphire:
1). Produce blue: for lighter sapphire, like heat-treated Sri Lankan sapphire, its color is very close to Indian cornflower sapphire. During identification, the inclusion characteristics of the gem can be observed by the instrument. The heat-treated sapphire may have ring Fissures, burnt filamentous inclusions, ring-shaped ribbons around dark mineral inclusions;
2). Weakened blue: mainly for darker sapphires, such as darker Shandong sapphires, Australian sapphires, Thai sapphires, etc. After this heat treatment, some dark tones are removed. Generally speaking, this effect is not as good as the blue effect. it is good;
3). Produce golden yellow: under oxidizing conditions, golden yellow sapphire can be produced;
4). Starlight sapphire is produced: filiform rutile crystals are produced through heat treatment to produce the starlight effect.
2. Thermal diffusion method is also called surface diffusion treatment method, which diffuses the color-causing ions to the surface of colorless or light-colored corundum at high temperature to produce:
1). Bright blue: Sapphire of this color is very similar to natural high-quality sapphire. During identification, the waistline, ridgeline, and cracks of the sapphire can be observed to be darker than other places;
2). Starlight sapphire: The color of this starlight sapphire is dark blue with gray-black tones, and there are red patches in the cracks. The surface of the sample can be seen to be red during oil immersion observation. In addition, the star lines are too uniform and symmetrical, not like natural sapphire.
3). Synthetic sapphire: At present, there are two main methods for synthesizing sapphire, one is the flame melting method and the other is the flux method. The flame melting method can produce star sapphire, which has the same characteristics as synthetic ruby.
