Sparks from an Angle Grinder

This is a photo of myself grinding a hinge off of an old road case.  You can see sparks resulting from the friction of the disk on metal.  This type of light source is very warm and is fire-like.  My right glove is reflecting a little bit of that light if you look close.  The oxidizing metal acts as a single source of light while at the same time being many small sources of light.

Recreating this effect on stage might be difficult unless pyrotechnics could be used with the assistance of electrical lighting.  This reminds me of the Rembrandt painting we looked at in class with regard to the apparent source of light.