Diorite
Diorite ( Greek διορίζειν diorízein "differentiate, demarcate") is a deep rock (" plutonite ") of dark to black, more rarely medium to light gray color. Diorites are never colored. Its volcanic counterpart is andesite . In terms of composition, diorite stands between granite and gabbro and is similar to tonalites .
Mineral composition
Diorite consists of a crystalline-granular mixture of
- Plagioclase (feldspar) with an anorthite content between 30 and 50%
- Amphibole
- Pyroxene or other mafic admixtures
and little chlorite , quartz may also be added in varieties . Of quartz diorite to quartz speaks in proportions of 5 to 20%. If the quartz content exceeds this value, another type of rock, a tonalite , is present. Furthermore, iron minerals, apatite , zircon and titanite are found in diorites as minor components . If the horn cover is replaced by the dark magnesia mica, it is called mica diorite .
Spherical diorite
A rarely occurring variant of diorite is the spherical diorite, a spherical rock or orbiculite (French: Diorite orbiculaire ) made of concentric spherical shells. The formation of such silicate orbiculites can be explained by the sudden hypothermia of an overheated magma . Radial crystal growth is characteristic. The growth rate of the crystals and the diffusion of the components in the melt determine the formation of the partially alternating shells, which are created by partial melting and recrystallization of other rock parts. It occurs on Corsica ( Sainte-Lucie-de-Tallano ) in Finland, Austria and Sweden.
Occurrence
The diorite forms corridors and sticks in the mountain, mostly in stages from the Archean and the Paleozoic . Occurrences in Europe can be found in Ruhla , Brotterode , on the Rosstrappe , on Kyffhäuser , in the Odenwald , in the Bavarian Forest , in the Mühlviertel and in the Iron Mountains of Bohemia , in Normandy and in Brittany .
The ancient Egyptian deposit of Mons Claudianus is a quarry landscape in the Wadi Umm Hussein east of the Gebel Fatira. The mining activities are said to have started in the time of Emperor Claudius (41–54 AD). An intensive period of mining existed in the reigns of Trajan (98–117 AD) and Hadrian (117–138 AD).
In addition to Ajaccio in Corsica (including a quarry south of Sainte-Lucie-de-Tallano ), spherical diorite also occurs in Finland ( Ylöjärvi-Pengonpohja near Kuru ), Slättemossa near Järnforsen in Sweden and in Häusler near Groß Gerungs in the Waldviertel ( Lower Austria ) in front.
use
Ancient uses for diorite can be proven in many ways. Be in Rome pillars of the Egyptian quarries of Wadi Umm Hussein at Caesar Forum , Pantheon , Trajan, Trajanforum, Palatine , Temple of Venus and Roma and at the Villa Hadriana . The Codex Hammurapi is written on a diorite stele.
Dark types of diorite were mainly used in the 1950s and 1960s, and are still used occasionally today as a material for tomb design. There are examples of uses of Czech grades for bridge facings, columns and facade design in Prague.
Most diorites take on a good polish, but are difficult to work with because of their excellent strength properties. For this reason, they are rarely represented in modern architecture. Occasionally, they are used for turned objects such as columns, water basins or vases. Ball diorites are processed by the souvenir industry.
Because of their good material properties, diorites are used in road construction.
Natural stone types
| designation | country | place | Explanations |
|---|---|---|---|
| Marble claudianum | Egypt | in Wadi Umm Hussein / Eastern Desert | ancient name |
| Travnik Grigio | Bosnia Herzegovina | at Travnik | |
| Itaoca | Brazil | State of Espirito Santo | |
| Nero Marcos | Brazil | State of Rio Grande do Sul | |
| Preto Redençao | Brazil | State of Ceará | |
| Tijuca | Brazil | Rio de Janeiro | |
| Fürstensteiner diorite | Germany | Bavarian forest | so-called titanium spot diorite |
| Grafenstein | Germany | Upper Franconia | a hornblende biotite dorite |
| Gronau | Germany | Odenwald | Quartz gabbrodiorite |
| Anzola | Italy | Piedmont | |
| Blazing Black | Finland | at Viitasaari | |
| Kuru Black | Finland | at Kuru | |
| Negro Arronches | Portugal | Santa Eulalia | |
| Oplotnica Zeleni | Slovenia | at Maribor | |
| Negro Burguillos | Spain | Badajoz Province | |
| Negro Batalla | Spain | Badajoz Province | |
| Negro Ochavo | Spain | Badajoz Province | |
| Negro Valencia | Spain | Badajoz Province | |
| Bubovice | Czech Republic | at Příbram | |
| Částkov | Czech Republic | Iron Mountains | |
| Hutberg diorite | Czech Republic | on Kaní hora (Hutberg) west of Žulová | |
| Skorošice or Slezký diorit | Czech Republic | at Šumperk | |
| Třeboň | Czech Republic | near Budweis |
literature
- Rosemarie Klemm , Dietrich Klemm : Stones and Quarries in Ancient Egypt . Springer, Berlin / Heidelberg / New York 1993, ISBN 3-540-54685-5
- Friedrich Müller : INSK compact. Ebner, Ulm undated
- Olavi Selonen, Veli Suominen: Nordic Stone. UNESCO, Espoo, Paris 2003, ISBN 92-3-103899-0
- Wolfhard Wimmenauer: Petrography of igneous and metamorphic rocks. Enke, Stuttgart 1985, ISBN 3-432-94671-6
