Sage or Dwarf only during the site phase at any Under-deeps site. Tap the sage or Dwarf. Tap the site if it is not already tapped. Sage or Dwarf may not untap until Vein of Arda is stored at a Haven [H]. Cannot be duplicated at a given site.
"...gems and crystals and veins of precious are glint in the polished walls..."
-LotRIII