Sources for the Crystal icon set are everywhere. They are at many places in KDE's CVS, so many, it's hard to download them. Artists more skillful with sketchbooks than CVS, will be gladly surprised that Frans Englich wrote a script which collects them all, and that Philip Scott provided a high speed server for the resulting zip.
Crystal sources may be at your home. Of course, visionary Everaldo and over productive Torsten made most icons, still, other artists made contributions too. For whatever reason, some of these sources are missing. If you ever made a Crystal SVG icon, and see the source is not in this archive, please send the vector source to: firstname.lastname@example.org. And of course, Everaldo too is interested in your Crystal icons: "Everaldo" <email@example.com>
Crystal sources are certainly to be found at the SUSE server: SVG sources not fully ready to commit to CVS, and even Everaldo's Illustrator files! See the Icon Guide for more information about this.
The sources are especially useful for artists, developers and for experimentation. Many icons, especially the smaller ones are hand-fixed after they are exported to pixels. Running the sources directly on your system will probably give poorer results than using the PNG version of the Crystal SVG set released by Everaldo himself.
Crystal sources may pop up in your head. Crystal SVG is one of the most popular icon set around. Join this project, help to make it more complete, and know your work installed on computers all over the world! A good starting point is the Icon Guide.
Which icons are missing? See the buglist.
With such a wealth of sources, your destiny is... to be inspired!