Cobblestone

Cobblestone is a darker block, often looking like a roughly paved area. This block doesn't occur naturally on it's own, but makes great walls for constructions such as castles and roads. Because of its dark color it is often used in pixel art to represent darker colors.

History
Cobblestone was removed in 0.0.19a, but returned in 0.0.20a. It was removed due to lack of room in the UI.