Item from The Witcher by Andrzej Sapkowski
An ancient elven artifact capable of opening a portal to summon the Naglfar — the key to forcing a confrontation with the Wild Hunt.
The Sunstone can force open a portal large enough to summon the Naglfar — the Wild Hunt's spectral ship — making it the most strategically important artifact in the war against Eredin. Using it essentially sends an invitation the Wild Hunt cannot refuse, dragging them from whatever world they currently haunt into a confrontation on the summoner's terms. This makes it a weapon of last resort: you don't activate the Sunstone unless you're prepared to fight everything that comes through the rift. The stone itself is ancient elven work, its facets catching light and refracting it into patterns that hurt to look at directly. Activating it requires specific astronomical conditions and a wielder with enough magical knowledge to survive the energy discharge.
A crystalline stone roughly the size of a fist, its surface faceted in geometric patterns that catch and refract light in impossible ways. When activated, it blazes with golden light.
Also known as: Sunstone, the Sun Stone