question:     What kind of glass does GRAV use?

GRAV uses the finest borosilicate, a type of glass with a high silica content that’s heat-tolerant and chemically inert.  These qualities make borosilicate perfect for pipes, as it can withstand and disperse heat from a lighter or torch and doesn’t pollute smoke in any way.  Some of our components, namely our nails and bangers, are made from quartz.  Quartz is 100% silica, making it even more durable than borosilicate.  However, it’s more expensive than borosilicate, which is why we only use it for smaller pieces.