NOT unbreakable. = nope. Harder to break = yes meaning "glass" of a great many types has a very exact durometer of what force (load force) it takes to break/shatter and this new glass type is simply harder to break than ordinary silica glass. "Unbreakable" is exactly like the saying of "bullet-proof" glass and there is no such thing. There is bullet rated glass = yes but no such thing as bullet proof.