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
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
Origin
England
USA, Australia
Discoverer
Unknown
Tornebohm
Etymology
From Old French esclate, from esclat (French éclat)
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Earthy, Mud-rich, Rough
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Not Applicable
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
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, Metallurgical Flux, Source of Magnesia (MgO)
Types
Not Available
Endoskarns
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Not Applicable
Grain Size
Very fine-grained
Fine Grained
Fracture
Splintery
Irregular
Streak
Light to dark brown
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Dull
Waxy and Dull
Compressive Strength
Not Available
Specific Gravity
2.65-2.8
2.86
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Not Yet Found
South Africa, Western Africa
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
United Kingdom
Others
Arctic
Not Yet Found
Deposits in Western Continents
South America
Brazil
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, Western Australia
All about Slate and Skarn Properties
Know all about Slate and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Slate and Skarn belong to Metamorphic Rocks.Texture of Slate is Foliated whereas that of Skarn is Earthy, Mud-rich, Rough. Slate appears Dull and Skarn appears Dull. The luster of Slate is dull while that of Skarn is waxy and dull. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Skarn is available in black, brown, colourless, green, grey, white 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 Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).