Diamond saw light-show.

Most of us rely on a diamond saw to prepare the stone for the sphere machine. Recently I was cutting a block of superb banded, clear and white, massive quartz to size. With the illumination off I could see a band of light shining through the flat, partly clear surface of the block. it appears as though light, and not sparks, is the cause. It is not unheard of that quartz under pressure can produce light so I think this might actually be the impact of the diamond particles in the blade being pressed against the rock. In fact the area where there would be most pressure, that is in the direction of cutting, would be where the pressure is greatest and the light most intense and not at a tangent. That is the case.

The imported image has been seriously changed by the blog software towards blue. It was originally pale yellow.