一種表面粗糙的灰色石材。 堅硬且耐風化，常用於基礎建築和簡易防禦工事，且易於加工。主要分佈於水邊和沙漠地區。
Stone with a rough, gray surface. Sturdy and resistant to weathering, it is used for basic construction and simple defensive structures, and is also easy to process. Commonly found near bodies of water and the desert.