/usr/share/kde4/apps/kwin/crystal.desktop is in kwin-style-crystal 2.2.1-2ubuntu1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | # KDE Desktop Entry
[Desktop Entry]
Encoding=UTF-8
Name=Crystal
X-KDE-Library=kwin3_crystal
|