Formation
Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.
  
Essexite is a type of igneous rock, which is usually dark grey to black plutonic rock. For the formation of essexite, suitable magma with exact composition of K, Ba, Rb, Cs, Sr should be produced.
  
Composition
  
  
Mineral Content
Clay Minerals, Pyrite, Quartz, Sulfides
  
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
  
Compound Content
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO
  
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Biological Weathering, Chemical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Coastal Erosion, Glacier Erosion, Water Erosion
  
Jasperoid and Essexite Formation
Formation of rocks is a long process and hence, Jasperoid and Essexite formation sounds very interesting. According to the formation, all rocks are divided into :Igneous Rocks, Fossil Rocks and Metamorphic Rocks. Igneous rocks form by crystallization of magma or lava. The magma is made up of various components of pre-existing rocks which have been subjected to melting either at subduction zones or within the Earth's mantle. Igneous rocks are generally seen at mid ocean ridges or in intra-plate hotspots. Sedimentary rocks are formed when sediments accumulate gradually. As the sediments are buried they get compacted as more and more material is deposited on top. Eventually the sediments become so dense that they form a rock. Metamorphic rocks are rocks which once existed as igneous or sedimentary rocks but have been subjected to varying degrees of pressure and heat within the Earth's crust. Get to know all about formation of Jasperoid and Essexite , composition of Jasperoid and Essexite and their transformation.