Formation
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Composition
Mineral Content
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
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50% - Metamorphic Rocks Rocks have it !
Types of Metamorphism
Impact Metamorphism
Weathering
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65% - Metamorphic Rocks Rocks have it !
Types of Weathering
Biological Weathering, Mechanical Weathering
Erosion
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77% - Metamorphic Rocks Rocks have it !
Types of Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion