Boston is a minimalist and functional icon theme focused on basic shapes, a reduced color palette and visual hierarchy.
Newaita Icons
Linux icon theme
Numix Icons
Beautiful icons for Linux
Obsidian Icons
Gnome Icon Pack based upon Faenza, optimized for dark themes
Qogir Icons
A flat colorful design icon theme for linux desktops
Vimix Icons
Vimix icon theme is based on Paper-Icon-Theme
Sardi Icons
Circle-style and minimalist icons
Zafiro Icons
Minimalist icons created with the flat-desing technique, utilizing washed out colors and always accompanied by white.
Paper Icons
Paper is a modern freedesktop icon theme whose design is based around the use of bold colours and simple geometric shapes to compose icons.
Papirus Icons
Papirus is a free and open source SVG icon theme for Linux, based on Paper Icon Set with a lot of new icons and a few extras, like Hardcode-Tray support, KDE colorscheme support, Folder Color support, and others.