Limestone

Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO₃). Limestone often contains variable amounts of silica in the form of chert or flint, as well as varying amounts of clay, silt and sand as disseminations, nodules, or layers within the rock.

So, with that, i bring to you an ambigram i meantioned before. I did this a LONG time ago; somewhere around the beginning of this year. So...