I've been using my sandblasting cabinet
(http://users.eastlink.ca/~howarde/Sand%20Blaster.html) for a while
now & have always used glass grit as an abrasive. One of the
neighbours had some cast wood stove parts he wanted to clean up & he
shows up with a couple of bags of sand to do it with. We loaded her
up & let rip whereupon I noticed that where the sand was impacting the
metal there was something that looked like a a pale blue spot of
light. It only showed when the nozzle was within an inch or so of the
metal. It was bright enough that I could see exactly where the sand
was hitting even through the dust & a rather hazy window.

Was I imagining it or is there actual light being generated?

If there is light is it electrostatic discharge or are the sand grains
exibiting some sort of piezoelectric effect from the shock??

Enquiring Minds Want To Know-

H.