The resource you should be setting is named iconPixmap. Try this:
Originally Posted by Database Administrator
BTW, the standard Athena widgets don't support color pixmaps (XBMs are black-and-white). But, if you switch to ://www.efalk.or you can use XPMs, which can have color. Note also, that, if you chose an picture with transparent background, the icon's background will be that of the xterm itself (what you specify with the -bg option, for example).
xterm -xrm '*iconPixmap: /vol/museprd/xref/icons/ChIMP.xbm'