MeliaeSVG is really cool icons for Linux distro's. It makes your Linux different from others. Author said It is Gnome Icon Set but It's name is MeliaeSVG.
To install MeliaeSVG Icons in Ubuntu 15.04/14.10/14.04/12.04/Linux Mint 17.1/17/13 open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:
To install Darkenza icons in any Ubuntu/Linux Mint open Terminal and copy the following commands in the Terminal: