Twilight of the Gods
Svartalfheim, or the home of the dark-elves, is a realm beneath the ground, down amongst the roots of Yggdrasil. The true dvergar dwell there, as do the dark-elves, though few living people have ever seen them. They are said to be night-dark and corpse-white, to be burned by the sun, and to devour sacrifices. It is rare that they are acknowledged – their counterparts, the Ljosalfar or light-elves, are far more popular subjects of veneration.
In many stories, svartalfar and dvergar seem to be almost interchangeable.