I always find silver in Rethban Caverns (Redridge) and Thengel Rock (Wetlands). But we're not talking about "farming" silver here because it's just too rare to be able to farm it. I'm talking 2 nodes, and maybe 1 or 2 respawns if I decide to stick around for a while. It's really not enough to be worthwhile selling it, but if you NEED it to actually make something those 2 spots are fairly reliable for me.
Edit: Also with silver I almost always get only 2 pulls off a node before it's used up.
Edited, Feb 20th 2007 12:09pm by Azrella