You can find this striped red rock in the Canyons, as a basic type of canyonstone.
A Stone Mining Cell is needed to mine this rock (and some other canyonstones as well).
Ruddy Canyonstone is necessary for crafting Ruddy Stucco Walls, and after that Patina Roofs, Patina Walls and Ruddy Stucco Windows that will be unlocked by crafting/taking Ruddy Stucco Walls.
To unlock the recipe of Ruddy Stucco Wall, you will have to craft Stucco Wall at first, which will be unlocked by mining/taking ordinary caramel Canyonstone.
Additionally to that, Ruddy Canyonstone can be used in other recipes that will accept different kinds of canyonstones, like Wood Gravel Wall, Barred Wood Window, Cobblestone or Mossy Cobblestone.
When Ruddy Canyonstones are placed as they are, Dustevils can spawn on or near them during the (ingame-)day, also - more rarely - Trogs or even Dried Leafis, ordinary Leafies and Night Leafies during the (ingame-)night.
Also Wood Treasure Chests might appear at night on this kind of block in completely dark areas, no matter where these blocks have been placed.