Mortar is a mix of Portland cement and sand and is useful for bedding masonry units which include concrete block, brick, and stone. Classic mortar also involves lime, which makes the mortar stickier, so it stays about the finishes of every brick or block mainly because it’s currently being positioned. https://www.whofish.org/Default.aspx?tabid=45&modid=379&action=detail&itemid=284671&rCode=33