Icon theme Numix Circle Icon is a package that contains all the icons for the most popular applications.
Currently theme Numix Icon Theme Circle has been updated to version 0.2 and compatible with producing Ubuntu 14.04, that fixes some bugs and adds support for many more icons.
Here is the theme Numix Icon Theme Circle into Linux Mint 16:
Installation into Linux Mint/Pinguy OS or others Ubuntu distrs:
sudo add-apt-repository ppa:numix/ppa sudo apt-get update sudo apt-get install numix-icon-theme-circle
It only remains to activate the icons: