Well, Dubdub (she said stepping with trepidation onto the realm of the expert who is absent at the moment), yes, I think your walloping story is on target--jade (nephrite, let me hasten to specify) won't shatter easily. A clue might be its monoclinic property: Of or relating to three unequal crystal axes, two of which intersect obliquely and are perpendicular to the third. (From Atomica.)

Oh, and yes, thanks, Sweet stales!