Khalk is the letter K
There is no rune poem for Khalk. It is a Northumbrian Rune.
Khalk is the cup, chalice or grail. The drinking utensil that holds liquids, but it is also the Loving Cup, the chalice of dreams and desires, and the Holy Grail whose draught can ease pain, bring healing, and gaining it fulfils desires and is the attainment of the quest. Khalk is the rune that gives us that taste of fulfillment that we seek, but at the same time it also goads us onward, showing us how much farther we need to go, until we gain that which is desired.