It's coal. A decent source of fuel.
Coal is a mineable ore which cannot be smelted, but is important for many crafting recipes. It cannot be refined in a Refinery - however, if one has access to a Sewing Machine, it can be combined with Poison to create Synthetic Material, which can be sold through Terramart Shipments for 30% of tooltip value (not as good as 50% of tooltip value given by Refinery, but not as bad as 20% of tooltip value given by merchants).
It can be found on all planets except barren planets, moons, and asteroid fields.
Upon picking up coal for the first time, S.A.I.L. will send the following message:
You discovered coal! You can turn coal into torches to light your way. The chance of fatal incidents is dramatically increased in the dark. Explore the crafting menu.
| /spawnitem coalore