Frostvein Shard

The Frostvein Shard is the signature material of the Arctic Plains: it drops as an uncommon reward from most mobs in that zone, so any farming session in the ice biome naturally builds a stock. There is no single farm target - the whole region feeds the supply.

Its headline use is as a summoning item: Frostvein Shards can be used to summon the Gelid Dweller, one of the game's summonable encounters. That makes it one of the few materials that directly creates content on demand rather than only sitting in recipes - if your group wants the Gelid Dweller's fight and drops, shards are the entry fee.

Beyond summoning, community documentation notes it is also used in certain crafting recipes, though the specific recipes are not itemized on the card yet. Between the summon use and crafting demand, it is worth holding a reserve whenever you are already grinding Arctic Plain enemies - the Quincy Schrift questline and other late progression steps route through this zone anyway.