1. Diamond identification: Diamond is the hardest substance among natural substances, and it can carve any other gem, but no other gem can carve it. The most accurate and reliable way to identify genuine and fake diamonds is to measure the thermal conductivity data with a "thermal conductivity meter", but the "thermal conductivity meter" is expensive.

2, agate identification: Nau can mainly be identified from the color, texture, transparency and weight of the pattern. High-quality agate has bright surface and clear stripe pattern, while fake agate is not bright enough and the color is too single. High-quality agate is hard and has few surface defects, while fake agate is soft and easy to leave scratches. Real agate has low transparency, while fake agate has high transparency.

3. Sapphire: Sapphire is characterized by uneven color, undeveloped polycrystal and strong dichroism. Sapphire produced in Myanmar is bright blue, because the inclusion can produce six or twelve starlight. Sapphire from Kashmir, India, is a kind of high-quality sapphire, which is cornflower blue and indigo blue with bright color. Sapphires from Sri Lanka, Thailand, China and Australia also have their own characteristics. Sapphire is fragile, so you should avoid bumping and bumping when wearing it.

4. Crystal identification: Rock crystals are clear and transparent, often containing cloud-shaped, star-shaped or flocculent gas-liquid inclusions, and often have microcracks. In addition, the rock crystal is polarized, and you can see the phenomenon of twin crystals, such as a crystal ball. Looking down from the top, there will be a double image. Synthetic crystal or glass products are uniform and pure in the body, without cracks, and often have small bubbles inside. Looking down at the sphere, you can't see the ghost of the line below. Through touch recognition, we can feel that the proportion of synthetic crystals is greater than that of rock crystals; Crystal stone feels cold and glass feels warm.

5. Identification of pearls: Identify whether pearls can be bitten by teeth. If you don't feel smooth and the nacre falls off when you bite, it means it's true. In addition, pearls can rub against each other. If the pearl surface is uneven and fuzzy, it will lose powder, and so on. From the hand feel, natural pearls give people a cool feeling when held in their hands, but after being held for a period of time, the temperature of pearls will change with the body temperature. But fake pearls will not feel obvious coolness, and the feeling in hand is greasy.