Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
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
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From Old French esclate, from esclat (French éclat)
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Dull
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
As Dimension Stone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone
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
Not Available
Not Available
Features
Host Rock for Lead
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Used
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Very fine-grained
Fracture
Uneven
Splintery
Streak
Light to dark brown
Light to dark brown
Porosity
Less Porous
Less Porous
Toughness
Not Available
1.2
Specific Gravity
2.46-2.86
2.65-2.8
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
South Korea
China, India, Turkey
Africa
Western Africa
Not Yet Found
Europe
Great Britain, Switzerland
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Others
Not Yet Found
Arctic
Deposits in Western Continents
North America
Not Yet Found
USA
South America
Not Yet Found
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Not Yet Found
All about Pseudotachylite and Slate Properties
Know all about Pseudotachylite and Slate properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite and Slate belong to Metamorphic Rocks.Texture of Pseudotachylite is Quench whereas that of Slate is Foliated. Pseudotachylite appears Dull and Soft and Slate appears Dull. The luster of Pseudotachylite is vitreous while that of Slate is dull. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that 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.