Limestone/ˈlaɪmstəʊn/ Definition 1 of 1Pro Tip 1/3Geological Origin Limestone forms from marine organisms' remains, imbuing it with historical significance. Geologists study limestone to understand Earth's history. Pro Tip 2/3Construction Material Limestone is valued in construction for its durability and aesthetic appeal. Many cathedrals boast intricate limestone carvings. Pro Tip 3/3Cultural Landmark Because it's used in iconic structures, limestone can be a symbol of heritage. Tourists visit the limestone ruins of ancient civilizations.