Welkynd Stones (Aldmeris for "sky stone/heaven stone"; literally, "sky child") are luminescent aquamarine crystals created by the Ayleids. The stones are pieces of cut and enchanted Meteoric Glass, a rare form of Aetherial Fragment. The stones contain the concentrated power of Mundus and were used as a means of storing magicka. Magically talented individuals can draw the power from the stone to restore their own magicka. The means of restoring power to a drained stone was lost with the death of the Ayleids; without this knowledge, the stones simply crumble to dust after being used. Welkynd Stones are prized by mages, and many remain to be looted from Ayleid ruins, where they are often placed atop pedestals for illumination.
Great Welkynd Stones are exceptionally large pieces of enchanted meteoric glass. A Great Stone was once located at the heart of each Ayleid city and acted as the source of the settlement's magical enchantments. Scholars speculate that the Great Stones were linked to the lesser stones, restoring and maintaining their power. Great Welkynd Stones were highly sought by mages following the downfall of the Ayleids; in time, all of the stones were plundered from their cities. The last Great Welkynd Stone was taken from the Ayleid city of Miscarcand in 3E 433, to be used by Martin Septim in a ritual to create a portal to Gaiar Alata. The stone acted as the polar opposite of a Great Sigil Stone and was destroyed in the ritual.
Like other types of meteoric glass, Welkynd Stones have the ability to grow and multiply if correctly cultivated. The Ayleids mastered the art of creating the crystalline structures and were beginning to cultivate them outside of their underground communities when they disappeared from history. Uncut Welkynd Stone crystals can occasionally be seen growing on the stone walls of subterranean Ayleid ruins. Lithnilian, an Altmer scholar, was the first to discover the crystals growing in a natural cave. Bramblepoint Cave was located in the Nibenay Basin. The discovery proved that, with the proper materials, magic, and research, the Welkynd Stone could adapt to any environment.
Dark Welkynd Stones were used by the Ayleids for security. The black crystals glow with red light, and cast powerful elemental destruction magic at trespassers who get too close. Many of these ancient traps continue to function, presenting a dangerous obstacle to adventurers exploring the ruins. Some Dark Welkynd Stones will power down if the intruder stops moving, although this method is unreliable.