Limestone high quality quarried limestone, called Indiana limestone. Many famous buildings in London are built from Portland limestone. Limestone was also a very popular building block in the Middle Ages in the areas where it occurred, since it is hard, durable, and commonly occurs in easily accessible surface exposures. Many medieval churches and castles in Europe are made of limestone. Beer stone was a popular kind of limestone for medieval buildings in southern England. Limestone and (to a lesser extent) marble are reactive to acid solutions, making acid rain a significant problem to the preservation of artifacts made from this stone.
Oamaru stone In Oamaru itself the stone is most commonly found as the primary construction material, with many of the town's more notable buildings (such as the Waitaki District Council building) showing its distinctive creamy colour. Its ease of working also appeals to sculptors and examples of Oamaru stone sculpture can be found throughout New Zealand. The source of the stone is a 40-metre thick deposit inland from Oamaru consisting of bryozoan limestone. Oamaru stone is limestone with a uniform granular creamy white consistency and colour. Predominantly (90%) calcium carbonate, trace chemicals within it include alumina (1.5%), iron oxide (0.5%) and silica