I was trying to follow Pinoy's "Engraved Button" tutorial and noticed that PSP X2 does not have the "Metallic" gradient, so I made one. You can download the one I made (
http://rightflyer.com/graphics/pspfiles/Metallic.grd - how do you change the link text on this board?), or make your own using these settings:

Ignore the "custom" color, just set your foreground to white and your background to black.
To create a new gradient:
1) Bring up the settings dialog for gradients
2) Click "Edit"
3) Click "New" and type "Metallic"
4) Enter the settings shown above
5) Save it
The "Metallic" gradient will now appear in your gradients list.