Were you able to find a lava rock? I can't find any in the wheel clan or black mountain clan caves, and as far as I can tell the inventory mod which supposedly makes the rocks appear in the garbage bins doesn't work with this version of arcanum (no rules folder).
Any help would be appreciated.
Ok, well I've solved my own problem it seems. I tried the hack that is supposed to put the lava rocks in the bins, however it didn't work for me. When I used the "invensource" hack available here
it worked for me, but ONLY in Tarant at the general store. Perhaps it will work elsewhere too, but it definitely didn't work in Ashbury for me.