Feather the selection and paint the highlights following the light source like I've painted on the image (you can variate, dont forget!) and don't forget to add subtle highlights (2 pixels wide in the end of the piece!).
For the shadows at this step they are a bit primary, do it like if you were doing a rivet, except that it gets cut in the middle, so paint the shadows opposing the light source again, also add some but very slight near the side highlights, to give depth.
We will leave the primary shadowing and highlights for now... now we shall select the inner circle (you can do it by unhiding the layer with the selection that we made at start, and with the magic wand tool click on the middle - the place where the supression will be), and feather it by 0.5 again.
Shadow the inner a bit, like you see in the image, the process is the same as the hole, but I will follow it though.
Shadow it again, but this time with a bit more strength in the direction of light source, to give depth.
This time put a white highlight around the ring that forms the shape, with again a very small brush with some opacity, and darken the interior even more.
One of the most importants, is to add the highlight oposing to lightsource, as you can verify here.
Now let's edit the light we have previously made, but make a small patch of shadow below the highlight, this will give a more sensation of depth and add a bit more shadow below the shape.
Add a more stronger shadow, and a small highlight with midtone selected, but make it subtle!
Now the hard part, add a very subtle highlight to the borders of the shape, and select the hole shape and select inverse (don't forget to feather the selection!), the start painting some shadows with the burn tool, just to get the general effect.
The basics are done, now all you have to do is to modify some lighting by mixing some dodges and burns in the right place, to give the effect of something spherical but at the same time conic
Now for the tricky part, we pick up the dodge tool again, and set its brush size to 1 pixel, put some low opacity, and flow Clockwise following the sphere shape, to make a some kind of brushed metal effect, do the same with some burns, but not so intense
Are you still there? Amazing! We are almost finished. For the final detailing on this part we will make a shape, any shape, could be anything inside the supression, I made a "j" and I selected it's transparency and used color burn again on the metal (don't forget...feather)
And to finalize, add this final highlight, a somewhat exagerated one, and finish some small details that you might want to change on the lighting.