Three hexes south, two southwest of Alakran.
Even those who believe devoutly in Mitra and other latter-day gods refer superstitiously to storm lightning, usually appearing only in the rainy winter, as the "arrows of Hurru" (the old Urig war-god); the heat-lightning that flickers across summer nights is known as "the banners of Hurru."
Among the rare phenomena to be seen in the sandy erg desert is the aftermath of a lightning strike that hits wet sand during the rainy season and creates small, knobbly glass pegs known as fulgurites. These relics are rapidly covered over by the dunes and erode in the course of time, but each hour's searching in a sandy region has a 1/20 chance to find one, subject to passing a Nature check at DC 15 (and disadvantage unless one is versed in the desert terrain).
Fulgurites are useful in making magical charms and certain alchemical mixtures, and are part of a secret recipe for creating lightning wands; most such wands created in the Urig cultural sphere will have a polished fulgurite for a tip. Due to these objects' great value to alchemists and wizards (100 gp) some unscrupulous wizards try to set up an industry of false fulgurites when they learn the lightning bolt spell. Alas, these synthetic creations are without magical force, having come from the hand of a mortal and not from dread Hurru himself.