Where does Ubuntu 14.04 LTS store LibreOffice icons ? I mean by that the icons used by the GUI of LibreOffice Writer, LibreOffice Calc, LibreOffice Impress...
The icons are stored in compressed files in the folder /usr/share/libreoffice/share/config
EG
2256 -rw-r--r-- 1 2308309 Aug 4 15:01 images_galaxy.zip
488 -rw-r--r-- 1 496912 Aug 4 15:01 images_sifr.zip
7268 -rw-r--r-- 1 7440250 Aug 4 15:01 images_tango.zip
The icons you can see depends on your selected icon theme.
The package name of such a theme or style is
libreoffice-style-...
List the installable or installed styles in your system via
$ dpkg -l libreoffice-style* | awk '/libreoffice-style-/ {print $2}'
libreoffice-style-andromeda
libreoffice-style-breeze
libreoffice-style-crystal
libreoffice-style-default
libreoffice-style-galaxy
libreoffice-style-hicontrast
libreoffice-style-human
libreoffice-style-oxygen
libreoffice-style-sifr
libreoffice-style-tango