Sagot :
QUARTZ
WHAT IS QUARTZ?
- Quartz. It is a glassy-looking hard substance with white streaks. Despite its hardness, with a Mohs hardness of 7, it is quite brittle.
Quartz
Quartz. It is a glassy-looking hard substance with white streaks. Despite its hardness, with a Mohs hardness of 7, it is quite brittle.