You can find this wine-red rock in the "striped"
Biomes, where it is one of the most common types of Canyonstones.
Stone Mining Cell is required to mine this rock and other types of Canyonstones as well.
Dark Canyonstone is required for crafting
Dark Stucco Walls, and after that Tin Roofs, Tin Walls and Dark Stucco Windows that will be unlocked after crafting Dark Stucco Walls.
To unlock the recipe for Dark Stucco Walls, you will have to craft
Stucco Walls at first, which will be unlocked after mining ordinary caramel Canyonstone that can only be found high up in Canyons. Dark Canyonstone will not unlock this crafting recipe.
Additionally to that, Dark Canyonstone can be used in other recipes that will accept different kinds of canyonstones, like
Wood Gravel Wall, Barred Wood Window, Cobblestone, Mossy Cobblestone,
When Dark Canyonstones are placed as they are,
Dustevils can spawn on or near them during the (ingame-)day, also Trogs or even Dried Leafis, ordinary Leafies and Pigsies.
Night Leafies and Night Pigsies may spawn on Dark Canyonstone during the (ingame-)night.
Wood Treasure Chests might appear at night on this kind of block in completely dark areas, no matter where these blocks have been placed.