(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.
In residential settings, switchable frosted glass is becoming increasingly popular in bathrooms and bedrooms. Homeowners can install it in places where privacy is essential, such as shower enclosures or bedroom windows facing a busy street. The ability to toggle between transparent and frosted glass allows occupants to enjoy sunshine and views when desired, yet guarantees seclusion when necessary. This functionality adds a modern touch to any home while ensuring comfort and tranquility.