Blue Glowing Sugar

What you need:

• white rock sugar (you need large sugar crystals)
  
• a hammer
• a (nearly) completely dark room
  

Instructions

Take your sugar crystals to a completely dark room. Hit the sugar with the hammer. While being crushed, the sugar crystals will glow blue. Not very bright and for a short moment only, but it will glow. You might need several tries to see it.

Notes

• As it is dark, pay attention what you hit with your hammer! Make sure nobody is hurt!
  
• For better orientation it helps if you have a desk lamp nearby, which you can switch on/off quickly.
• When hitting the sugar crystals with the hammer, small sugar pieces will fly around. To avoid this you can put the sugar into a small transparent plastic bag. But the effect might be harder to see then.
• If you have difficulties to see the glowing, wait a couple of minutes until your eyes have adopted to the darkness.