The limestone is a sedimentary rock composed of the mineral calcite, a form of calcium carbonate. For the first time the limestone is classified by Robert L. Folk and Robert J.Duham.
Generally limestone is classified in three types:
- Regular limestone - used as a construction material or yielding lime and cement
- Shell stone - one can distinguish inside it shell residues of various species. Because of its beautiful aesthetics it is used mainly for panelling walls, facades, fountains etc.
- Chalk – this type of limestone is very soft and it is mainly used for the chalk production.
The limestone is widely used in architecture. Many landmarks across the world, including the Great Pyramid and its associated complex in Giza, Egypt, are made of limestone. So many buildings in Kingston, Ontario, Canada were constructed from it that it is nicknamed the 'Limestone City'. In the late 19th and early 20th centuries train stations, banks, big stores and other structures from that era are normally made of limestone.
Vratza Limestone - High Quality Limestone from Bulgaria
Starting back in the 19th century, Vratza limestone is mined in the Northern Bed of Mezdra syncline. It is a calcite lime with comparatively high substance of quartz.
Vratza limestone is a type of natural Bulgarian limestone, that has unique features – it is extremely weather-resistant, easy to process and possesses rare aesthetic qualities. These features makes it a perfect material for outdoor application – outdoor, paving, cladding and decorations, as well as for interior use like limestone fireplaces, interiour decorations, limestone staircases and furniture.
If we take a closer look at the facades of the old classical buildings, we would find out the features of a compact, homogenous stone that is impressive with its warm creamy colour – rain- and cold-resistant throughout time. Vratza limestone is an excellent building stone for humid regions. This type of limestone is hard enough to resist weathering but usually soft enough to be processed (cut and carved) by stonemasons.
Tests show that in terms of strength and frost resistance Vratza limestone exceeds the other limestone types.