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
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
Origin
New Zealand
New Zealand
Discoverer
Unknown
Unknown
Etymology
From Greek mulōn mill + -ite
From German which means hornstone
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Granular, Platy
Color
Black to Grey
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Appearance
Dull, Banded and Foilated
Dull
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Landscaping, Roadstone
for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Blastomylonites, Ultramylonites and Phyllonites
Biotite hornfels
Features
Surfaces are often shiny
Smooth to touch
Archaeological Significance
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Porphyroblasts
Andalusite
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Fe, Mg
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Cleavage
Conchoidal
Perfect
Specific Gravity
2.97-3.05
3.4-3.9
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Cameroon, East Africa, Tanzania, Western Africa
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Queensland, Western Australia
Mylonite vs Hornfels 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 Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Mylonite and Properties of Hornfels. Learn more about Mylonite vs Hornfels in the next section. The interior uses of Mylonite include Decorative aggregates and Interior decoration whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Mylonite and Hornfels, they have various applications in construction industry. The uses of Mylonite in construction industry include For road aggregate, Landscaping, Roadstone and that of Hornfels include For road aggregate, Roadstone.
More about Mylonite and Hornfels
Here you can know more about Mylonite and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Mylonite and Hornfels consists of mineral content and compound content. The mineral content of Mylonite includes Porphyroblasts and mineral content of Hornfels includes Andalusite. You can also check out the list of all Metamorphic Rocks. When we have to compare Mylonite vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Mylonite is available in black to grey colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Mylonite is Dull, Banded and Foilated and that of Hornfels is Dull. Properties of rock is another aspect for Mylonite vs Hornfels. The hardness of Mylonite is 3-4 and that of Hornfels is 2-3. The types of Mylonite are Blastomylonites, Ultramylonites and Phyllonites whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Mylonite is white while that of Hornfels is . The specific heat capacity of Mylonite is 1.50 kJ/Kg K and that of Hornfels is 0.84 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 Hornfels is heat resistant, impact resistant, pressure resistant.