|Release date||7 February 2012 (Update)|
|High alch||0 coins|
|Low alch||0 coins|
|Store price||Not sold|
|Examine||It looks thicker than normal glass.|
Robust glass is an untradeable resource created by melting red sandstone in a robust glass machine, which can be accessed after As a First Resort.... Making robust glass from sandstone has no Crafting requirement and grants no experience. Players with level 89 Crafting can create potion flasks from robust glass using a glassblowing pipe to receive 100 Crafting experience. Players may boost their level if below 89 but can not be assisted.
It is possible to obtain Strange rocks through making flasks.