Definition
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Discoverer
Unknown
Unknown
Etymology
From Greek mulōn mill + -ite
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Banded, Rough
Color
Black to Grey
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Glassy or Pearly
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Landscaping, Roadstone
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Blastomylonites, Ultramylonites and Phyllonites
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Surfaces are often shiny
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Mineral Content
Porphyroblasts
Quartz, Silicon
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Shiny
Waxy and Dull
Specific Gravity
2.97-3.05
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
2.6-4.8 g/cm3
2.7 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Kenya, Morocco, South Africa, Tanzania
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
-
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
USA
Canada, Mexico, USA
South America
-
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, Queensland, South Australia, Western Australia
Mylonite vs Chert Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Mylonite vs Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Mylonite and Properties of Chert. Learn more about Mylonite vs Chert in the next section. The interior uses of Mylonite include Decorative aggregates and Interior decoration whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Mylonite and Chert, they have various applications in construction industry. The uses of Mylonite in construction industry include For road aggregate, Landscaping, Roadstone and that of Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Mylonite and Chert
Here you can know more about Mylonite and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Mylonite and Chert consists of mineral content and compound content. The mineral content of Mylonite includes Porphyroblasts and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Metamorphic Rocks. When we have to compare Mylonite vs Chert, the texture, color and appearance plays an important role in determining the type of rock. Mylonite is available in black to grey colors whereas, Chert is available in black, brown, green, grey, red, white colors. Appearance of Mylonite is Dull, Banded and Foilated and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Mylonite vs Chert. The hardness of Mylonite is 3-4 and that of Chert is 6.5-7. The types of Mylonite are Blastomylonites, Ultramylonites and Phyllonites whereas types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Mylonite and Chert is white. The specific heat capacity of Mylonite is 1.50 kJ/Kg K and that of Chert is 0.74 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Mylonite is heat resistant, impact resistant, pressure resistant whereas Chert is heat resistant, impact resistant, pressure resistant, wear resistant.