Is there such a things as 'pure energy'?

Well...not like some kind of 'thing' that you can touch. Even light itself is only one kind of energy. Energy is nothing more than the ability for something to do work. If I hold a hammer above the ground, its speed is zero, but it has a lot of 'potential energy' which is invisible, until I release the hammer. Then this 'potential energy' is steadily transferred into kinetic energy and this is 100 percent complete at the instant before the hammer strikes the ground. You can't see pure potential energy, and the only way you can see pure kinetic energy is because you can see something moving....but from this you have no idea how much kinetic energy there is in the thing just by looking at it. 'Pure' energy is a vague term that doesn't have much of a physical meaning to it.