Mechanically-speaking, Svirfneblin in Pathfinder: Domain are identical to those found in the Pathfinder Advanced Race Guide p204. You can also find Racial Information on them on the d20pfSRD website.
XP Cost: 24,000
Tulun Svirfneblin: Long ago, the Svirfneblin and the Gnomes used to be a single race, one that was known as Nix. Developing as a people over the millennia beneath the earth, a growing number of their people became curious as to what the surface held. Eventually, a rift developed between the Nix and just over fifty percent of the population left in a mass exodus to the surface, with those who stayed behind feeling that their brothers and sisters had betrayed their traditions and roots. Those who went to the surface changed over the years, eventually becoming the modern Gnomes, whereas the those who remained behind adapted to the sunless environment and eventually became the Svirfneblin. When they eventually encountered the Duregar and the Shen’ari conflict erupted, but the wily Svirfneblin took the least casualties on the war of three-fronts. Instrumental in the establishment of The Elder Council, it was the Svirfneblin who convinced the Duregar and Shen’ari to invest in the idea for the preservation of all their races.
Place of Origin: All Svirfneblin come from Mor-Denoch, almost exclusively.