How much does it cost to buy crystal glasses in Tianjin?

Generally, the number of rock crystals ranges from 1000 to more than 5000.

Synthetic crystals range from dozens to hundreds.

However, the crystal itself is expensive, not to mention how beautiful it is to wear. Crystal does not absorb and block ultraviolet rays and infrared rays, so it will feel that the lens is relatively cold, which is not as good as a pair of ordinary ultraviolet sunglasses in this function.

Crystal lenses are not optical lenses, which are harmful to the eyes. Crystal is a natural crystal time. Because of its hard texture and some impurities, it is not only expensive, but also not as pure and transparent as ordinary optical glass and has poor clarity. Crystal lenses made of impure crystals contain radioactive element radon, which is harmful to human health. Secondly, the absorption rate of crystal lens to ultraviolet rays is only 19%, and the absorption rate to infrared rays is only 34%, resulting in a large number of ultraviolet rays and infrared rays entering the eyes. Wearing crystal glasses in the sun for too long will make you feel tired. It is also one of the inducing factors of cataract. In addition, the thermal conductivity of crystal glass is 10 times that of ordinary optical glass, so it is wrong to say that crystal glass is cool, and of course it has no effect of dispelling fire and diminishing inflammation.