It’s hard to find something that is truly unbreakable. Even Bruce Willis’s seemingly invincible character in “Unbreakable” had a breaking point. The same is true of tempered glass.
Tempered glass is glass that has undergone a special thermal treatment to make it stronger than regular glass. Tempered glass is used in car windows, refrigerator trays, and as a component of bullet-proof glass. Many people assume that tempered glass is indestructible due to its versatile applications. While tempered glass is statistically stronger and more resistant than plain glass, it will break with enough force.
Ironically, one of the major selling points of tempered glass is that when it does break, it shatters into smaller, duller pieces instead of larger, sharper shards. Despite this, people continue to abuse the tempered glass on their furniture and are appalled when it breaks.
So take the baby (and the pets) off the glass coffee table and remember that just because it’s been treated, it’s still glass and still very delicate.