Definition
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
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Origin
England
New Zealand
Discoverer
Abraham Gottlob Werner
Unknown
Etymology
From Old French esclate, from esclat (French éclat)
From Greek mulōn mill + -ite
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Foliated
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black to Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull, Banded and Foilated
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
for Road Aggregate, Landscaping, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
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
Creating Artwork, Gemstone, Jewelry
Types
Phyllite, Schist, and Slate
Blastomylonites, Ultramylonites and Phyllonites
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Surfaces are often shiny
Archaeological Significance
Formation
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Porphyroblasts
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Splintery
Conchoidal
Streak
Light to dark brown
White
Porosity
Less Porous
Highly Porous
Cleavage
Slaty
Conchoidal
Specific Gravity
2.65-2.8
2.97-3.05
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.6-4.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
China, India, Indonesia, Saudi Arabia, South Korea
Africa
-
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Deposits in Western Continents
Deposits in Oceania Continent
Australia
-
Central Australia, Western Australia
All about Slate and Mylonite Properties
Know all about Slate and Mylonite properties here. All properties of rocks are important as they define the type of rock and its application. Slate and Mylonite belong to Metamorphic Rocks.Texture of Slate is Foliated whereas that of Mylonite is Foliated. Slate appears Dull and Mylonite appears Dull, Banded and Foilated. The luster of Slate is dull while that of Mylonite is shiny. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Mylonite is available in black to grey colors. The commercial uses of Slate are 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 and that of Mylonite are creating artwork, gemstone, jewelry.