B. glassy

This is a new style of drinking glass, the borosilicate double wall glass.

Borosilicate glass is an “engineered” glass developed specifically for use in laboratories and applications where thermal, mechanical and chemical conditions are too harsh for standard, household-type soda lime glass. Some common names of borosilicate are PyrexTM by Corning and DuranTM by Schott Glass. Like most glasses, the main component of borosilicate glass is SiO2. The big difference is it has boron oxide and various other specialty elements instead of “soda and lime” to give it its outstanding qualities.