The Spectral Pickaxe is crafted within an Infusement Altar. Spectral Pickaxes are able to mine out a 3x3x1 area of any overworld stone type (Excluding Obsidian).
On release, the Pick accidentally was able to be enchanted but was later fixed.
Spectral Tools can only be enchanted through incredibly rare villager trades and can only be repaired by using the same version of the Spectral tool (Spectral Pickaxe + Spectral Pickaxe).
In the development of the spectral tools, there was a thought to have the pick turn into a random pickaxe between wood and diamond.
The spectral pickaxe can be crafted in the infusement altar using 2 spider skulls, and 2 creeper skulls in any assortment. You can craft it after unlocking the recipe within the Infusement Book for 300XP levels and by placing a Perfect Diamond in two of the four available slots, a regular Diamond Pickaxe in another and a Tourmaline Block in the other. Crafting the pickaxe will consume 1000 ticks of fuel(1 Dense Neutron Star or half of the fuel provided by a White Point Star).