Animating the actual weapon in 2d

Hi,

I am currently playing around with weapon animations in unity2d. I have a simple setup of a Player game object and a weapon object as a child and the actual weapons as children of that game object.

The actual attack animations are fine but I am not sure how to approach animating the weapon itself. Lets say its a massive hammer with some floating crystals or whatever around it and I want them to constantly keep floating around the hammer head. I have a sprite sheet for the animation but if I try to add an animation to the weapon it uses the Player as the controller gameObject. Can I somehow animate my weapon so that no matter what I am using it in (walking, attacking, etc. further animations) it will still keep animating itself?

The second animator on the weapon object and separate animations for it.
There may be simpler ways, but I would do so.