1, laboratory method

Detecting sapphire glass is very similar to identifying jewelry, and the instruments and equipment used are the same. The most commonly used instrument for jewelry identification is refractometer, which can measure the refractive index of the detected object.

Although sapphire glass is artificial, its refractive index is 1.76~ 1.77, just like natural glass. Because sapphire glass is crystal, it also has a birefringence of 0.008, which can be seen clearly by rotating the polarizer on the eyepiece during the test. ?

Flat glass is best observed, spherical glass is not very beautiful, so refractive oil should be coated when testing.

The refractive index of mineral glass is about 1.52, which is easy to distinguish from sapphire. It has no birefringence. ?

Another method is to use a polarizer, and all crystals can be detected with a polarizer, such as crystals. Sapphire is also a crystal. When the polarizer is rotated, the light will change alternately with a period of 90 degrees.

But if you use a polarizer to check the watch glass, you must take out the whole movement and expose the watch glass. But some non-sapphire watch glasses may also have polarizing effect, because they are also made into crystals, such as crystals.

2. Look at the logo of the watch

If it is a regular brand watch, sapphire glass is usually printed on the back cover of the watch, which is expressed by English sapphire or sapphire crystal. Nowadays, it is very common to use sapphire glass even for fake watches and counterfeit watches.

3. Look at the hardness of the watch glass

To test the hardness of the watch glass, you can use a sharp metal object like a needle to draw the most inappropriate eye on the edge of the watch glass. It feels hard, and there is a feeling that metal objects are floating over. The glass is not scratched, it should be sapphire glass, but ordinary glass.

Extended data:

Sapphire identification method

The most common sapphire on the market is glass. In fact, it is relatively easy to identify glass. Glass is shaped at high temperature, naturally shrinks after cooling, and the plane is concave inward. This kind of depression is not easy to find with the naked eye, so a magnifying glass must be used. When using a magnifying glass, you can't focus in a straight line, but focus obliquely, so it is easy to find the concave surface. The concave surface is usually glass.

The polishing of precious stones usually achieves a very flat effect. Another identification method is that there are many kinds of inclusions in glass, the most common one is bubbles, while gems have no bubbles. Bubbles in glass can be found with a magnifying glass of 10 times.

There is also a sapphire that acts as a synthetic sapphire. The identification method is to first look at the texture and whether the texture structure is naturally crystallized. Rock crystal is often messy, so it is generally genuine.

However, the crystallization of synthetic sapphire is often very orderly. Of course, many synthetic sapphires are clean and flawless, usually fakes. Because there are always some impurities in natural gems, there are almost no clean ones. This synthetic sapphire is often dazzling in color and superficial in luster, without the deep feeling of natural color. Natural gemstones are high in color purity, not dazzling, and their brilliance is naturally emitted from the inside out.

References:

Baidu encyclopedia-sapphire glass

References:

Baidu encyclopedia-sapphire