As good an image editor GIMP is—out of the box, it can fall short of Photoshop at times. That said, you can use plugins to extend GIMP's functionality, and these make it even more powerful than ...

You can also add your own textures to GIMP by placing the images in the Patterns folder. To find or configure the Patterns location on your computer, select "Folders" from the GIMP Preferences window.

Although GIMP does not include a diamond texture option, as of June 2012, experiment with digital patterns, paint brushes and filters to superimpose a sparkling effect.