Right. He says that glass is the same as quartz, but it isn't. It's got other stuff in it to reduce the melting point and improve other working characteristics.

Right. He says that glass is the same as quartz, but it isn't. It's got other stuff in it to reduce the melting point and improve other working characteristics. Most everyday glass is soda-lime glass or (less commonly than in the past) lead glass ("crystal"). Lab glass is often borosilicate glass. All are pretty durable, but not anything remotely approaching pure quartz.