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
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
History
Origin
New Zealand
England
Discoverer
Unknown
Abraham Gottlob Werner
Etymology
From Greek mulōn mill + -ite
From Old French esclate, from esclat (French éclat)
Class
Metamorphic Rocks
Metamorphic 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
Foliated
Color
Black to Grey
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Dull
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
for Road Aggregate, Landscaping, Roadstone
As Dimension Stone
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
Types
Blastomylonites, Ultramylonites and Phyllonites
Phyllite, Schist, and Slate
Features
Surfaces are often shiny
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
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.
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Composition
Mineral Content
Porphyroblasts
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Regional 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
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
3-43-4
1
7
👆🏻
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Splintery
Streak
White
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Shiny
Dull
Compressive Strength
1.28 N/mm230.00 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
Slaty
Toughness
-
1.2
Specific Gravity
2.97-3.052.65-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.6-4.8 g/cm32.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
1.50 kJ/Kg K0.76 kJ/Kg K
0.14
3.2
👆🏻
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, Turkey
Africa
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
-
Europe
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Others
-
Arctic
Deposits in Western Continents
North America
USA
USA
South America
-
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-