Re: Could you please tell me the frequency at which glass breaks?

I would love to answer your question with an easy answer.  Unfortunately, 
this question has no simple numeric answer.  Each glass have a different 
frequency to break at.  Glass is made mostly of sand, but it includes many 
other materials which give it a distinct color or hardness.  Glass in the 
windshield of a car is different than the windows of a car.  These 
different compounds have different resonance points.  Often you can hear 
the tone at which the glass will break by running a finger around the rim 
of a fine wine glass, or tapping it gently when it is suspended.  If this 
tone is repeated *exactly* and at a very high volume, the glass will 
resonate at that frequency and may break.  Good luck in your searching!

      More info on glass making can be found at this site:
http://www.ironandglass.com/howglass.htm
      If you still would like an approxamate answer to your question, 
please ask the glass companies at these addresses:
http://www.peg.thomasregister.com/olc/peg/msgform.cgi?f609-691-3090

                                   -Marcy LaViollette