Mineral glass

The term mineral glass is used to distinguish normal glass from softer and lighter plastic glass or from harder sapphire glass in certain areas .

This is the case with watches in order to differentiate the watch glass used from the much softer plastic glasses and the much harder sapphire glasses, as well as with glasses.

As a rule, it is normal flat glass , as is also the case e.g. B. is used for window panes. Untreated it has a hardness of around 400 Vickers and is therefore around 20 times harder than plastic.

Hardened mineral glass is made more resistant on its surface through special manufacturing processes (e.g. special heating or steaming ) (see e.g. Gorilla Glass ). It has a hardness of around 900 Vickers. Sapphire crystal, on the other hand, has a hardness of around 2000 Vickers, but is also more expensive.