The Unbreakable Wineglass
Behold the Unbreakable Wineglass (and after you behold it, it's okay if you bedrop it):
Kwarx glass is handblown crystal and is supposed to retain lustre and transparency as well as being unbreakable.
It is certainly robust. David Cobbold, who presented the glasses (pictured), said 'They are virtually unbreakable.' He then banged his on his table to illustrate the point. Journalists enthusiastically followed suit, but none succeeded in breaking the glass.
Would it be immature of me to suggest that the Unbreakable Wineglass could be the newest practical joke at Jewish weddings? Stomp that!