This tutorial uses the gradient plug-in
The gradient we will be using can be downloaded from here (right click the link and save in the …\PhotoFiltre\Plugins\Degrade folder)

Create a circular selection. Hold down the shift key to create a even circle

Open the gradient plug-in and open sdc metal 001 gradient. Position it as so

Click Selection in the menu bar, then click contract and choose the width that you want the metal border to be. For this tutorial we will be using 5, but as you can see, other settings work as well (denoted in the numbers)

Open the gradient plug-in and turn the gradient in the opposite direct it was before

Go back to Selection » Contract and use the same width as before

Open the gradient plug-in, again.
Change the number of colors to 3

The middle color will be the color of your choosing
The left color will be a darker version of that color
and the right color will be white.

Change the angle to 90,00

Now, create a small flattened circle selection at the bottom of the innermost circle

Open from the menu bar and click the center color of the gradient in the middle. Your settings should be similar to this:

Now, create a long flattened circle selection at the top of the entire orb

Open from the menu bar and use settings similar to this: