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.
Shining Stone Community Action Shining Stone Community Action Shining Stone Community Action (SSCA; Chinese: 社区参与行动) is a Beijing-based non-profit organization whose mission is to engage citizens in public decision making. The organization works in accordance with the International Association for Public Participation's (IAP2) seven core values for the practice of public participation. The organization acts on the local level and throughout China to promote sustainable participatory governance reforms with the intention of making more exceptional, democratic, and efficient decisions. For that reason, SSCA has adopted western methods of public participation (for example, open space, community organizing, or mediation) in China. The NGO was founded