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
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
History
Origin
New Zealand
-
Discoverer
Unknown
Johann Gottlob Lehmann
Etymology
From Greek mulōn mill + -ite
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Clastic, Splintery
Color
Black to Grey
Black, Brown, Buff, Green, Grey, Red, Yellow
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Muddy
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
for Road Aggregate, Landscaping, Roadstone
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Creating Artwork, Pottery
Types
Blastomylonites, Ultramylonites and Phyllonites
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Features
Surfaces are often shiny
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Jantar Mantar in India
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.
Composition
Mineral Content
Porphyroblasts
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Ca, Fe, Mg, Silicon Dioxide, Sodium
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Physical Properties
Hardness
3-43
1
7
👆🏻
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
-
Streak
White
White
Porosity
Highly Porous
Highly Porous
Luster
Shiny
Dull
Compressive Strength
1.28 N/mm295.00 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
Slaty
Toughness
-
2.6
Specific Gravity
2.97-3.052.2-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm32.4-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.50 kJ/Kg K0.39 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
Bangladesh, China, India, Russia
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Others
-
-
Deposits in Western Continents
North America
USA
USA
South America
-
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia