Fill 0% on the layers.
Blending Options-Gradient Overlay

HomePage Icons Pack in Photoshop CS

Gradient?s parameters.

HomePage Icons Pack in Photoshop CS

Take the next tool and make another circle
with the parameters from next picture.

HomePage Icons Pack in Photoshop CS

Fill 0% on the layers.
Blending Options-Stroke

HomePage Icons Pack in Photoshop CS

Gradient?s parameters.

HomePage Icons Pack in Photoshop CS