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  2. Quartzite - Wikipedia

    en.wikipedia.org/wiki/Quartzite

    Quartzite can have a grainy, glassy, sandpaper-like surface. Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. [1] [2] Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts.

  3. Metamorphic rock - Wikipedia

    en.wikipedia.org/wiki/Metamorphic_rock

    A metamorphic facies is a set of distinctive assemblages of minerals that are found in metamorphic rock that formed under a specific combination of pressure and temperature. The particular assemblage is somewhat dependent on the composition of that protolith, so that (for example) the amphibolite facies of a marble will not be identical with ...

  4. Quartz - Wikipedia

    en.wikipedia.org/wiki/Quartz

    Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. [10] Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation ...

  5. Foliation (geology) - Wikipedia

    en.wikipedia.org/wiki/Foliation_(geology)

    Gneiss, a foliated metamorphic rock. Quartzite, a non-foliated metamorphic rock. Foliation in geology refers to repetitive layering in metamorphic rocks. [1] Each layer can be as thin as a sheet of paper, or over a meter in thickness. [1] The word comes from the Latin folium, meaning "leaf", and refers to the sheet-like planar structure. [1]

  6. Metamorphism - Wikipedia

    en.wikipedia.org/wiki/Metamorphism

    Metamorphic rocks are classified by their protolith, if this can be determined from the properties of the rock itself. For example, if examination of a metamorphic rock shows that its protolith was basalt, it will be described as a metabasalt.

  7. Metamorphic zone - Wikipedia

    en.wikipedia.org/wiki/Metamorphic_zone

    In geology, a metamorphic zone is an area where, as a result of metamorphism, the same combination of minerals occur in the bedrock. These zones occur because most metamorphic minerals are only stable in certain intervals of temperature and pressure .

  8. Baraboo Quartzite - Wikipedia

    en.wikipedia.org/wiki/Baraboo_Quartzite

    Baraboo Quartzite is a Precambrian geological formation [1] of quartzite, found in the region of Baraboo, Wisconsin. While pure quartzite is usually white or gray, Baraboo Quartzite is typically dark purple to maroon in color, due to the presence of iron ( hematite ) and other impurities. [ 2 ]

  9. Metasedimentary rock - Wikipedia

    en.wikipedia.org/wiki/Metasedimentary_rock

    In geology, metasedimentary rock is a type of metamorphic rock. Such a rock was first formed through the deposition and solidification of sediment. Then, the rock was buried underneath subsequent rock and was subjected to high pressures and temperatures, causing the rock to recrystallize. The overall composition of a metasedimentary rock can be ...