Recently I made +2 silver nuggets. I was getting zip all SP from ore to nuggets and I had a pile of +1,2,3 ore from ranking up mining so I picked up the rank 27 secondary tool (ragstone? silt? w/e) and decided to give it a go. If the nuggets increase in quality, I'd assume that the ingots would too.
Ferrish Draiodoir - Figaro Server
75BLM 75WHM 75PUP Garuda (quit May 2008)
Kelly's Fockleyr Gaelg - Baarle (Manx Gaelic): Ferrish - fairy, elf, naughty child; hand-steel.