This is a very well executed photograph. The sharpness of the sparks themselves is breathtaking, and the position of the hands is very good as well. I think it's very cool that you didn't manipulate the photo.
4 stars for originality because similar things have been done, though this is a unique twist.
5 stars for technique because the lighting and sharpness of the photo show that you know what you're doing with the camera and the elements of the scene.
Overall, this is an amazing shot and I'm glad to have found it to add to my favourites. Keep up the good work!