Ruby (Unrefined Gemstone)

is a Crafting resource used for the Alchemy skill. It can be further crafted into cut gems that can be socketed into crafted chest armor and weapons on an Alchemy Table. A socketed gem adds attunement to that gem's magical element while the equipment is worn or wielded. This stacks with attunement from passive skills.

Found
Various Gems can be found sometimes from loot from Troll creatures or occasionally harvested from Small Ruby Crystal, Medium Ruby Crystal and Large Ruby Crystal resource nodes.