Irish limestone
Irish Blaustein (ger .: Irish Blue Limestone ) is a blue-gray limestone from Kilkenny in Ireland , of the carbon originated 370 to 325 million years ago. It is a culturally and historically significant natural stone from Ireland, which is also used internationally and in Germany today.
Emergence
The Irish Blue Limestone occurrence extends under Ireland except under Counties Wicklow and Counties Antrim , and the rock is subject to more than half the area of the island.
This limestone was formed in a shallow bay in the warm waters of the Iapetus . The bay was in front of a large land mass about 5 degrees north of the equator in which fossils were deposited. About 325 million years ago the bay fell dry and the hard, fine-grained limestone was created through diagenesis , in which the fossils were shattered. Due to the movements of plate tectonics , this limestone deposit is now in Ireland.
Rock description and mineral inventory
The gray color of the Irish limestones was created by the finely distributed carbon that was embedded in the calcite crystals . Due to the different processing of natural stone surfaces , this can range from gray for coarse sanding or from dark blue to dark black for polishing.
The deposited lime mud consisted of fossil remains of sea lilies , which kept their pure white to gray color and they contrasted as grains and inclusions in the dark matrix. If there are no fossil components, the bluestone is completely black. The lime content ranges from 94% to 98%, while the dolomite content is only 2%. Silification resulted in bulbous flint inclusions with a diameter of up to 10 cm. In addition to the hardening of the limestone by overlaying, stylolite was formed , whereby the calcite crystals were dissolved and the finely distributed carbon was excreted.
Occurrence and use
The Irish limestone banks are flat because there was no mountain formation in central Ireland. Since this limestone is extracted in different rock banks, there are different gray tones. This limestone has been quarried in various quarries around Kilkenny, including neighboring Carlow , for centuries .
The Irish bluestone is used in today's architecture in exterior and interior areas for facade cladding, as floor panels, stairs and window sills as well as in horticulture. In Ireland it was mainly used as a solid building block for historical profane and clerical buildings and in stone carving. Due to weathering processes , it turns gray again in the outdoor area, provided it is polished and irrigated.
Irish bluestone, like all limestones, is sensitive to acids.
Technical specifications
- Specific weight: 2700 kg / m³
- Compressive strength: 126 N / mm²
- Water absorption: 0.93%
- Flexural strength: 141 N / mm²
- Breakout strength: 4.91 kN
- Frost resistance: yes
- Wear resistance / volume loss: 28 cm³ / 50 cm².
Web links
- kilkennylimestone.ie : Irish bluestone with images of uses
Individual evidence
- ↑ irish-genealogy-toolkit.com : Blue limestone. Irish natural stone. Ireland and landscape. Geology , accessed January 11, 2011.
- ↑ Karlfried Fuchs: Natural stones from all over the world, discover, determine, use . S. 186. 2nd volume Callwey, Munich 1997, ISBN 3-7667-1267-5 .
- ↑ These tests were carried out by the Institute for Building Research at RWTH Aachen University (test report NRA 2380 of February 19, 1991) and the Wismar building materials test center (test report no. 3405/05 of March 4, 2009).