We are certain that everyone reading this knows some facts about glass.
Not that you may be a glass expert, but, more because you will come across glass almost every hour of every day.
As for some of the common facts about glass, you are likely to know they include glass being clear, glass having a smooth surface, glass being delicate and at risk of smashing if it is hit by a hard object, and also that glass can cut your skin if you catch a sharp edge of it.