What are Stone Giants in Norse mythology?

Question

I found the name of a stone giant in Norse mythology named Hrungnir who was made out of stone. Are they a type of Jotunn or is this a singular instance?

https://en.wikipedia.org/wiki/Hrungnir

Answer 1

There doesn't seem to be a clearly defined race of stone-giants in the Old Norse corpus. In fact, Snorri Sturluson, who in his Skáldskaparmál gives the most detailed account of Hrungnir's duel with Thor, always refers to the giant using the term jǫtunn, which is usually translated as 'giant'. He does describe some of his body parts as being made of stone:

Hrungnir had a heart that is renowned, made of solid stone and spiky with three points just like the symbol for carving called Hrungnir’s heart has ever since been made. His head was also of stone.
_{Snorri Sturluson, Skáldskaparmál 17, translation by Anthony Faulkes}

However, such attributes cannot be taken as proof that he belongs to a whole new class of beings. Bear in mind that throughout the Old Norse corpus, giants receive various attributes depending on the narrative needs of the myths in which they are featured. Hence, Þjazi could shapeshift into an eagle, Starkaðr had eight arms, Útgarða-Loki was huge, etc.

Answer 2

Yeah. I made this mistake too. Despite how much Google generalizes it, he wasn't like the Stone Giants you know from D&D or LotR. Hrungnir wasn't crafted out of stone like Ullikummi (https://en.wikipedia.org/wiki/Ullikummi) or stone turned to flesh like Galatea (https://en.wikipedia.org/wiki/Galatea_(mythology)). It's more like Darth Vader with his cybernetics. He was a natural Jötunn who had certain body parts made of stone. Namely his shield, his head, and his heart (said to be a jagged, three-corned piece of stone). A lot of sources will say he was "Made of stone". This was likely an oversimplification of the translation. The writers of the story probably didn't feel like saying "containing a head, heart, and shield of stone" every time. So, they chose to use a phrase like "his body, consisting of stone", and the translations got it wrong. As far as I can tell, this was the only occurrence of something like this among their race.