What are watch crystals made of?
There are 3 categories of watch crystals: Plexi crystals, mineral crystals and sapphire crystals. Each of them has different characteristics, different application ranges and furthermore different fashion aspects. However, there are different quality standards within the categories. Plexi crystal Also referred to as hesalith, acrylic glass or plexiglass. It consists of Polymethylmethacrylate (PMMA). It is lightweight, therefore not very likely to shatter but most likely to become scratched. Minerals The chemical formula is silicon dioxideSiO2. Good mineral glass is not used for window panes. While manufacturing, the surface of good mineral crystals is hardened during a complicated chemical process. Minerals are harder than plexi glass, they are osmotic and do not yellow. But also minerals can be shattered. This can be very harmful to the movement, as small splinter of glass can damage it. Sapphire Among the crystals, sapphire is the hardest substance. Sapphires are manufactured synthet
