HEART OF STONE

Hrungner had, as is well known, a heart of stone, sharp and three-sided; just as the rune has since been risted that is called Hrungner’s heart. Even his head was of stone. His shield was of stone, and was broad and thick, and he was holding this shield before him as he stood at Grjottungard waiting for Thor. His weapon was a flint-stone, which he swung over his shoulders, and altogether he presented a most formidable aspect. On one side of him stood the giant of clay, who was named Mokkerkalfe. He was so exceedingly terrified, that it is said that he wet himself when he saw Thor.

- Prose Edda (Thor and Hrungner)