The science behind glass fragmentation

[StellarChip]

Hello all,
I was wondering if anyone can point me in the direction to information regarding what is actually happening inside the a break to the glass. I've seen some pretty fragmented chips before and was wondering whats going on at a very small scale. Why is there so much seeming damage that occurs inside the break that doesn't extend to the surface? What happens when a rock strikes the glass that causes it to become fragmented and not just knock a smooth divot out of the surface? Any help with finding this information would be appreciated. Thanks in advance!
Mark C Brown

[Glasseye]

I haven't been able to find any video so far on how glass breaks when impacted but I did find a really good video on how laminated windshields/windscreens are made. You can find it on " You Tube" input " How It's Made - Windshields" for a good 5 minute informative video. Notice when the interlayer is first fitted it is a milky colour, that is why old, contaminated damage on a windshield, returns to that colour.

[ChipperFixer]

StellarChip, one place that may help you understand the physics of glass and how it reacts during fragmentation is in the art of flintknapping, as strange as it may sound glass has the same qualities as many cherts and obsidians used in making arrowheads. Google flintknapping, there are hundreds websites and videos. I've made many arrowheads from glass. Its so easy a caveman can do it.