The appearance of glass and crystal are very similar, but they are two completely different substances. The main differences are as follows:

  1. Different materials

　　Crystal is a crystal of silica, and glass is just a molten mixture containing silica.

  2. Different efficacy

　　Glass only has a decorative function. In addition to the decorative function, crystal also has a piezoelectric effect, which has a special function of maintaining health.

　　3. Different prices

　　 The high-quality crystal looks clear and translucent when looking at the light. There are no small bubbles or water lines inside, so it is expensive. Therefore, the quality of the crystal is closely related to the price.

　　4. Different physical properties

　　(1) Crystal is a crystalline body with high hardness (Mohs level 7), while glass has a low hardness (Mohs level 5.5), crystals can make marks on the glass, but not vice versa.

　　 (2) The crystal is a crystalline body with good thermal conductivity, and it will feel cold when licked with the tip of the tongue. The glass is warm.

　　 (3) It is distinguished by polarizing lens. Crystal can transmit light, but glass cannot.

　　 (4) The high-quality crystal looks clear and translucent when looking at the light. There are no small bubbles or water lines inside, so it is expensive. Therefore, the quality of the crystal is closely related to the price.

　　 (5) The processing technology is different. The glass can be formed by hot casting, saving materials and labor, and low cost. Crystal is a crystalline body and cannot be reversed after being heated and melted, so hot casting cannot be used, but cold working methods such as cutting and grinding can only be used.

1. Wipe or wash the crystal crafts you want to identify. After they are dry, touch the crafts with the tip of your tongue. If there is a cold feeling, it is a crystal product, and if it has a warm feeling, it is a glass product. During the test, try not to hold the sample with your hands or place the sample near a heat source (in the sun, by the stove), so as to avoid errors caused by the temperature rise of the sample.

  2. Use a magnifying glass to observe the handicrafts. Inside the glass, there are often swirling or arc-shaped lines caused by uneven melting, but there is no crystal. In addition, there are often many bubbles in glass and few in crystal.

　　3. For the crystal ball, you can put it on the newspaper and look at the newspaper below from the top of the crystal ball. If it is a real crystal, the writing on the newspaper will have double shadows. In the case of glass products (including crystal glass), there is always only one image of the handwriting on the newspaper.

　　4. For crystal glasses, it can be checked in a polarizer. Adjust the polarizer to the orthogonal position. At this time, the field of view is completely black. Then place the crystal glasses between the upper and lower polarizers. The lens and the polarizer should not be strictly parallel. You can tilt it slightly so that there is one lens and the polarizer. Cross the angle, and then turn the spectacle lens. If it is made of real crystal crafts, there will be obvious brightness changes in the field of view. If it is always dark when rotating, the spectacle lens is a glass product or crystal glass (glass made of low-quality crystal).

　　 5. When traveling, the polarizer is inconvenient to carry. You can bring two polarizers (or two small polarizers for photography) with a diameter of less than 40mm. When measuring, one person holds two polarizers so that they are orthogonal and completely black. Human hands hold the glasses and rotate them between the two polarizers. If there is a significant change in brightness, it is a real crystal product, and if the darkness does not change, it is a glass product.