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
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
History
Origin
New Zealand
-
Discoverer
Unknown
Alexandre Brongniart
Etymology
From Greek mulōn mill + -ite
From Amphibole + -ite
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated
Banded, Foliated, Massive
Color
Black to Grey
Black, Brown, Green, Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Foliated
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
for Road Aggregate, Landscaping, Roadstone
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Blastomylonites, Ultramylonites and Phyllonites
Hornblendite
Features
Surfaces are often shiny
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.
Composition
Mineral Content
Porphyroblasts
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Physical Properties
Hardness
3-46-7
1
7
👆🏻
Grain Size
Fine Grained
Medium to Coarse Grained
Fracture
Conchoidal
Irregular to Conchoidal
Streak
White
White to Grey
Porosity
Highly Porous
Less Porous
Luster
Shiny
Vitreous to Dull
Compressive Strength
1.28 N/mm290.00 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
-
Toughness
-
2.3
Specific Gravity
2.97-3.052.5
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm32.85-3.07 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.50 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Saudi Arabia, South Korea
Russia, Turkey
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Germany, Greece, Iceland, Norway, Poland
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
South Australia, Western Australia