The Resonating Wand is an item added by Astral Sorcery. It is used to activate Astral Sorcery's crafting altars, as well as the Starlight Infuser. It is also used to detect Rock Crystal Ore underground as white motes emanating over them from the ground at night.
When using a crafting table near one of the strange crystals in the ancient ruins, the crystal instinctively focuses a single ray of light onto the table. The light is dim, yet it seems to have an effect on the malleability and density of certain materials on the crafting table.
This unlocks various crafting recipes that are not normally possible, the simplest object which of which that can be crafted is a basic wand that can be used to interact with various types of starlight sensitive devices.
The resonating wand also has some other curious properties. When it is held in either hand at night, it vibrates and emits energetic sparks of white light that gather in seemingly random locations around the surface of the land. Nothing seems out of place or special on the surface though...