This button graphic is created exactly the same as the header graphic, just smaller. Up the colors to 16 million. Delete mask and don't merge with layer. Flood fill with your background color or pattern. Add a new layer.
Flood fill selection with white.
Add another new layer. Create a jewel as outlined above and make a copy. Position jewels over the circular portion of the graphic. Save as a jpg. Click here to download the jeweled presets and the bar graphic.