Drenov Grič black limestone: a heritage stone from Slovenia

Abstract

Abstract Drenov Grič black limestone is considered to be one of the most beautiful Slovenian natural stones due to its black colour interwoven with white veins. Over the centuries, it has been extracted from two major quarries located west of Ljubljana. One of these quarries has been declared a valuable natural feature of national importance and is protected as a natural monument. This well-stratified, Triassic (Carnian) micritic limestone occurs in 10–80 cm thick beds with thin marl interlayers. The limestone occasionally contains abundant fossil bivalves, gastropods and ostracods. It is relatively rich in carbonaceous and bituminous organic matter, which is responsible for the black colour of the stone. The stone has been widely used in Slovenian monuments. Many indoor and outdoor architectural elements have been constructed using this limestone, particularly during the Baroque period, which was known for its extensive use of black limestones in other European countries as well. The most significant use of this limestone has been recorded in sculpted portals and altars. Some important buildings, which were decorated utilizing this stone, have been declared cultural monuments of local or national importance. Use of this limestone was also documented in other European countries (Italy, Austria, Serbia) and worldwide (USA). When exposed to climatic influences, chromatic and salt weathering are recognized as the main deterioration phenomena for this limestone when used in monuments.