4. UV Protection Tempered insulated glass units can be treated with low-emissivity (low-E) coatings, which block a significant percentage of harmful ultraviolet (UV) rays. This protection helps prevent fading of furniture, flooring, and artwork indoors, extending the lifespan of these items.
(8) With hair inspection: Put the crystal on a hair, the human eye can see the double shadow of the hair through the crystal, it is natural crystal, mainly because the crystal has birefringence.
Conclusion