These twelve silvery spikes are found in a wallet of soft, furry Vhuurmi hide. Their points are chisel-shaped, and the shafts spiral to a loop at the end that a rope can easily pass through. The metal feels soft and warm to the touch, though it resists all mark or imprint. The spikes gleam dully in even the dimmest light.
With a slight tap, one of these spikes can be driven into any normal surface -- stone, ice, metal, wood, and so on -- as long as the medium is thick enough to hold the spike. (They will not enter thinner strata; their magic is of holding and bonding, not destruction.) Once in place, no normal force can remove the spike -- only powerful magic or the destruction of the surface will cause the hold to yield. These spikes can be driven into more exotic walls -- adamantium, tears, human dreams, the wings of fey suicides -- though success is not assured. Depending on the strength and enchantment of the surface, the character using the Sprial Mountain Anchor might need to roll under their level on 1d8, 1d10, or 2d6.
A single Spiral Mountain Anchor can be used to spike shut any normal door. Once done, the door is wizard locked as if by a magician of the same level as the user. The character who drove in the spike, though, has no special ability to cause the door to open. Only those abilities and magics that bypass a wizard lock can open the portal. The destruction of the door might (50/50) result in the Spiral Mountain Anchor becoming free from its bond and usable once again. There is a chance that one or more Spiral Mountain Anchors could spike shut great valves, portals between worlds, the doors of perception, and other ontological openings.