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What is a Protolith rock?

The original rock that has undergone metamorphism is called the protolith. Protolith can be any type of rock and sometimes the changes in texture and mineralogy are so dramatic that is difficult to distinguish what the protolith was. Note that diagenesis and weathering are also a changes in form that occur in rocks.

Which can serve as Protolith?

All rocks (igneous, sedimentary and, even other metamorphic rocks) may serve as the protolith for metamorphism. Metamorphic processes take place in the solid state, that is, no melting may occur.

What are the factors that affect the pressure acting on a metamorphic rock as it forms?

Temperature and pressure. Temperature and pressure are important factors in determining the new minerals that form in a metamorphic rock. Different minerals form under different pressure and temperature conditions.

What are the two main types of texture for metamorphic rocks?

TEXTURES Textures of metamorphic rocks fall into two broad groups, FOLIATED and NON-FOLIATED. Foliation is produced in a rock by the parallel alignment of platy minerals (e.g., muscovite, biotite, chlorite), needle-like minerals (e.g., hornblende), or tabular minerals (e.g., feldspars).

Is Clay a metamorphic rock?

Low grade metamorphic rocks tend to characterized by an abundance of hydrous minerals, minerals that contain water within their crystal structure. Examples of low grade hydrous minerals include clay, serpentine, and chlorite.

What are the examples of metamorphic rocks?

Common metamorphic rocks include phyllite, schist, gneiss, quartzite and marble. Foliated Metamorphic Rocks: Some kinds of metamorphic rocks — granite gneiss and biotite schist are two examples — are strongly banded or foliated.

What is the process of metamorphic rocks?

Metamorphic rocks are formed through the transformation of pre-existing rocks in a process known as metamorphism (meaning “change in form”). The original rock, or protolith, is subjected to heat and pressure which cause physical, chemical and mineralogical changes to the rock.

What are the 6 steps of the rock cycle?

Igneous, sedimentary, and metamorphic rocks on the surface of the earth are constantly being broken down by wind and water….When the particles are carried somewhere else, it is called erosion.

  • Transportation.
  • Deposition.
  • Compaction & Cementation.

How can you tell a diamond from a rock?

The only hardness test that will identify a diamond is scratching corundum. Corundum, which includes all rubys and sapphires, is 9 on the hardiness scale. If your suspected diamond crystal can scratch corundum, then there is a good chance that you found a diamond. But NO OTHER HARDNESS TEST will identify a diamond.

Which geodes are most valuable?

The rarest and most valuable geodes contain amethyst crystals and black calcite.