Kalk is one of the Northumbrian Runes
It is the letter K. The version I use looks like an upside down eolhx rune, but with straight lines coming from the angled ends.
It’s name can mean several things, but the most commonly agreed to meaning is cup, chalice or grail.
There is no rune poem for Kalk.
Kalk, as the cup or grail, is the container that holds fluids that can be nourishing, intoxicating or poisonous. It can be the loving cup, a container that we pour or love and desires into, seeking their fulfillment as we then drink deep. It is bottomless, and can quench the thirst of the seeker.
It can be the cup that holds the mead of poetry and inspiration, drinking deep to bring ecstasy and enlightenment, as well as skill with words, song and persuasion.
It could be the sangreal as the Holy Grail, but also as the container of the royal blood, As the Holy Grail, it brings healing and rejuvenation. As the royal blood it raises up the power within, arousing the divine spark in humanity which makes miracles possible.
It can be all those things as the item of a quest, an goal or attainment, that as the focus of desire, helps to show how far along the path one has traveled, and also how far one has to go.