Red Hat/Fedora old but excellent icons. I repackaged the old rpm, fixing name change in modern Gnome/Mate desktop. Things are not yet perfect but it's better than the original outdated one.
To install these icons, simply extract the tarball in ~/.icons
These icons will deliver their best with gtk theme like the TraditionalOk series from Mate or the Clearlooks-phenix theme (https://github.com/jpfleury/clearlooks-phenix)
For archlinux users, this theme is available in the same state in AUR: https://aur.archlinux.org/packages/bluecurve-icon-theme/