Granophyr
Granophyr is a fine or coarse-grained crystalline deep rock with a high proportion of silicate , a plutonite . This deep rock belongs to the igneous rocks . Its chemical composition corresponds to that of rhyolite as surface rock .
colour
In terms of color, it is usually light or grayish.
composition
It is mainly composed of feldspar and quartz . Lower proportions have darker minerals such as pyroxene and olivine . But they usually do not make up more than 5% of the total mass.
Under the microscope you can see that feldspar and quartz have grown together.
Granophyr is similar to granite , but it is much coarser-grained.
Occurrence
Granophyr is found primarily in powerful intrusions . For example, you can spot it at Vestrahorn and Eystrahorn in the southeast of Iceland . It is also found near Lake Lugano in Switzerland.
See also
Individual evidence
- ^ K. Sæmundsson, E. Gunnlaugsson: Icelandic Rocks and Minerals. Reykjavík 1999, p. 46
- ^ K. Sæmundsson, E. Gunnlaugsson: Icelandic Rocks and Minerals. Reykjavík 1999, p. 46
- ^ K. Sæmundsson, E. Gunnlaugsson: Icelandic Rocks and Minerals. Reykjavík 1999, p. 46
- ^ [1] E. Reusser, B. Kuhn: Geologie des Tessin, in: Kristalle. Special Show Mineral Fair Zurich 2009; Accessed November 5, 2010