Make a new document (100 x 100). Make a new layer. Draw a circle with the Elliptical Marquee tool. Save your selection (Select>Save Selection>Click OK)
Fill with medium gray. Feather by 4 pixels. Invert selection and press the "M" key. Now move the selection 2 pixels to the right and 2 pixels down, with the arrow keys on the keyboard.
Now go to Edit>Fill>100% White, click OK.
Move selection up 4 pixels and to the left 4 pixels. Fill with
black (Edit> Fill>100% Black)
Load " Alpha 1" (Select>Load Selection>Click OK.) Inverse selection and press delete.
Make a Vertical rectangular selection from the top of the circle to the bottom like shown. Fill with 60% Black (Edit>Fill>60% Black).
Move the selection 2 pixels to the right, Fill with 100% white. Move it back 2 pixels and fill with 60% Black and deselect
Ok lets Brighten it up a little bit: Go to Image>Adjust>Brightness, I entered for Bright +23 and Contrast +12, Click OK.
Last rotate, Edit>Transform>Rotate, Hold down shift and rotate it 45 degrees.
Finished