tempered glass
TEMPERED GLASS
A type of "Safety Glass" processed by a controlled thermal treatment that increases the strength of the glass multiple times. In the event the glass breaks, it crumbles into small granulate style pieces instead of possible dangerous jagged shards. All tempered Cast Glass Images products meets the American Standards Institute Specifications (Code ANSI Z97.1).

(Image illustrates typical small granular chunks of broken tempered glass)