Attuned Shards are attuned to a specific Warp Plate and form the connection between two Warp Plates when inserted into one another. Each newly placed Warp Plate comes with one Attuned Shard by default, but you can create additional shards by placing another set of ingredients into the Warp Plate.
Crafting
Additional attuned shards can be created within a Warp Plate by placing a piece of Flint in the center and four pieces of Warp Dust around it.