Formation
Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.
  
Taconite is a type of sedimentary rock formed when a river carries or transports pieces of broken rock as it flows. When the river reaches a lake or sea, its load of transported rocks settles or deposits at the bottom of sea or lake.
  
Composition
  
  
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
  
Hematite, Magnetite, Quartz
  
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
  
Fe, Iron(III) Oxide, Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Rhyolite and Taconite Formation
Formation of rocks is a long process and hence, Rhyolite and Taconite 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 Rhyolite and Taconite, composition of Rhyolite and Taconite and their transformation.