Book excerpt: This literary ‘Swiss army knife’ on limestones provides descriptions and illustrations to explain the origins and uses of these important deposits. The book discusses their compositions and largely organically driven origins, as well as the environments in which they form, including both marine and land-based systems. Microscopic examination reveals the secrets of their subsequent development to form rocks. A brief explanation considers new views on their unique stratigraphy. Limestones are the fundamental ingredient for cement manufacturing and provide both building stones and aggregates. Landscapes that include limestones form iconic, and locally protected, karst scenery, with the distinction of generating some of the most intractable hydrogeological and foundation problems, illustrated by case studies. They provide reservoirs for ~50% of the world’s oil and gas reserves and locally host mineral ores; examples include lead-zinc-barite-fluorite, and copper. The closing chapter discusses the conservation of geological and geomorphological assets in Sites of Special Scientific Interest, with some lithologies designated as Heritage Stones.