Topsoil

Topsoil is a block in Lunacraft that covers the surface of your moon. It's a very unique block.

General Information
Like Dirt, Topsoil turns into Dirt when you mine it; Topsoil is the only block that doesn't drop itself after harvesting or mining it. The player is therefore unable to place Dirt back into the world and have it look like it originally did by normal means. Interestingly, if you can obtain the block from the Brown Mob's explosion, placing it in the Scanner shows nothing.

If you can manage to obtain the block, you'll want to stay in your world for as long as possible. This is because if you leave the world and re-enter, all Topsoil in your inventory will turn into Dirt. Topsoil is also, so far, the only Material in Lunacraft where multiple other blocks can transmute into it from Alchemy. It is also the only unstackable block in the game.

Geology
Hills are almost always covered in Topsoil blocks; however, the player can occasionally find Dirt or Gravel at the surface of them.