One circular device made from this material is described by the word "watch".
One circular device made from this material is described by the word "watch". Modern processes for manufacturing it float a layer of it atop molten metal. The most prevalent type of this material is rich in lime and soda. This material must be formed by rapid quenching, so that no crystal structure forms; one example of this in nature is the volcanic rock obsidian. Boron oxides are a major component of most laboratory equipment made from this material, as is silica; that particular variety is called Pyrex. This amorphous substance is manufactured by "blowing" and is transparent. For 10 points, name this material that is used to make flasks and beakers. 
One circular device made from this material is described by the word "watch".
glass [accept borosilicate glass; accept Pyrex glass; prompt "Pyrex"] 