Deep beneath the earth, in the half-dark of shafts and forges, lies Svartalfheim – the world of the black elves, as the dwarves are also called. From here come the greatest treasures of the gods: the spear Gungnir, the ring Draupnir, the hammer Mjölnir and Sif's golden hair.
The name (Svartálfaheimr, ‘home of the black elves’) is closely bound to the dwarves and their underground workshop Niðavellir, the ‘dark fields’. In the sources, dwarves, ‘black elves’ and ‘dark elves’ often blur into a single group of skilful beings of the deep.
Without Svartalfheim the power of the Æsir would not exist in this form. Here the sons of Ivaldi made the ship Skidbladnir and the spear Gungnir; here the brothers Sindri and Brokkr won, in a wager, the boar Gullinbursti, the ring Draupnir and Thor's hammer. And here Freyja's famous necklace, the Brisingamen, was dwarf-wrought. Whoever wants the finest work must go down to the dwarves.
“Then sought the gods their assembly-seats, / the holy ones, and council held, / to find who should raise the race of dwarfs / from Brimir's blood and the legs of Blain.”Völuspá 9, translation after Henry Adams Bellows (public domain)
Mjölnir – Thor's hammer · Midgard · Jötunheim · The Norse pantheon · The Nine Worlds.
Snorri Sturluson, Gylfaginning, Skáldskaparmál (c. 1220). Völuspá (Dvergatal), English public domain: Henry Adams Bellows (1923). Scholarship: Rudolf Simek, Dictionary of Northern Mythology; John Lindow, Norse Mythology.