Crystal Shards are also placeable in nearly any position (on walls, floors, and ceilings), though they are not nearly luminous enough to replace other light sources, and placement has no other functional effect. Although new Crystal Shards will only spawn on Pearlstone blocks in the Cavern layer, once harvested they can be placed anywhere. Crystal Shards will not spread Hallow on their own.
Crafting all items, including only one color of 晶光刃 (excluding consumables), requires a total of 115 Crystal Shards. Add 250 for all the other Phasesaber colors.