Aery icons are based on Elementary icons but most of the icons are created by Rho-Con-Linux. A beautiful and complete icon set for Linux distributions. This icon set is specially made for Elementary OS but it can be used with any Linux and with all kind of dark or light themes. It contains more than 6500+ icons in different sizes. Also checkout icons collection.
You can use Unity Tweak Tool, Gnome-tweak-tool or Ubuntu-Tweak to change icons.
To install Aery 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 Aery icons in Debian/any Ubuntu or Linux Mint version open Terminal (Press Ctrl+Alt+T) and copy the following commands in the Terminal:
Source: Aery icons