(2) Tongue licking: Even in the dog days of hot summer, licking the natural crystal surface with the tongue also has a cold and cool feeling. Fake crystal, there is no cool feeling.
4. Etching and Engraving This technique involves carving intricate designs onto the surface of glass, often using acid or abrasive materials. The finished product can range from simple patterns to detailed illustrations, making it a beloved method for both functional pieces and decorative art.