The "Glass" filter does a nice job at this effect.
FILTER>Glass:
Distortion=20
Smoothness=1
Texture=Tiny Lens
Scaling=50%.
I applied this to 2 layers and set the top one to Highlight. Then applied the Unsharp Mask to the lower layer to harden the lines a little.
You can tweak the brightness & contrast of the lower layer to your own tastes.
You can use the Bevel & Emboss filter to create a 3Dish text effect. Then just create the diamond effect on the layers above that.
And to make the really shiny effect, use the "sparkle" brushes from the default brush palette, and paint some sparkling highlights all over the diamonds --
in a fairly random fashion. Use smaller sparkles for around the edges and in the center, and larger ones for a few specific highlights.
I didn't have a lot of time to slap one together, but here's a quick example of the steps i just mentioned. Any questions just ask.
And here's the source PSD file for the example image below. It can be examined for specific details.
Bling Bling dude! (
266kb) B7
[excited]