Strange light when burning

[Eudaimonium]

Ok just a minute ago I was burning some dark-blue electrick tape when I noticed that then burning (I have 2 lenses, one from a cheap red pointer, other from burner, diode is from 16x burner, i made a focus point about a 2 cm from aperture exit, dot is a 1mm or so),
when I noticed, that during excesive smoking (of tape of course) there are some strange light flashes, I thought it was just white smoke, maybe a spark or short flame from tape, but when I looked more closely, there is white and blu-violet light flashes from source of smoke!
I thought it has something to do with color of the tape, I burned a piece of black rubber, same thing happens!!
It's like... tiny, maybe half of 1mm sparks, but only white and blue-violet color, appearing randomly.

Anybody has any explanation?!

 

[chido]

You can see that more clearly if you have protection goggles on. Here's the thread discussing that subject.

 

[heruursciences]

The sparks are the material getting heated white hot

 

[lazerguy]

But why does not the same thing happen when burning with an extremely focused green? :-? I've only noticed it with my red laser.