The two main differences are as follows:
1. The ingredients are different. Lead-free glass generally contains potassium, most of which are high-end handicrafts and are marked on the outer packaging, while lead-containing glass contains lead, that is, crystal glassware commonly found in some supermarkets and street stalls, and its lead oxide content can reach 24%.
2. The refractive index is different. Lead-free glass has better refractive index than traditional lead-containing crystal glass, and more perfectly shows the refractive performance of metal glass; for example, some ornaments of various shapes, crystal wine glasses, crystal lamps, etc. are made of lead-containing glass.
3. Different heat resistance. Glass can generally withstand very high temperatures, but generally has poor resistance to extreme cold and heat. Lead-free crystal glass is a glass with a high expansion coefficient, and its resistance to extreme cold and heat is even worse. If you make tea with boiling water in a particularly cold lead-free glass, it is easy to burst.
4. Different impact resistance. Lead-free glass is more tough than lead-containing crystal glass, that is, impact resistance.
Good glass products should have the following characteristics:
1) It is colorless and transparent or slightly greenish.
2) The thickness of the glass should be uniform, and the size should be standardized.
3) There are no or less defects such as bubbles, stones, waves, and scratches.
When purchasing glass, the user can put the two pieces of glass flat together to make them match each other.
In addition, it is necessary to carefully observe whether there are bubbles, stones, waves, scratches, etc. in the glass. The distance between the good quality glass is 60 cm, and the backlight is observed with the naked eye. Large or concentrated bubbles are not allowed, and no corners or cracks are allowed. The maximum angle of the wave bars and lines on the glass surface should not exceed 45 degrees; it is better to have less scratches and sand.