Ysgith rune

Can be purchased from Haggard in Vergen. Although classified as a crafting component by the game, there are no known diagrams which utilize this item.
To use a rune, Geralt simply drags it over to one of the rune slots on a suitable sword in the inventory panel.
de:Ysgith-Rune
fr:Rune d'Ysgith
it:Runa di Ysgith
ru:Руна из Ийсгита
Category:The Witcher 2 weapon enhancements