Definition
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
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
USA
England
Discoverer
Unknown
Abraham Gottlob Werner
Etymology
From 17th century, because of its greasy feel and use like a soap
From Old French esclate, from esclat (French éclat)
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Polished
Foliated
Color
Black, Black to Grey, Green, 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
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Jewellery, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
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
Metamorphic rock
Phyllite, Schist, and Slate
Features
Host Rock for Lead
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
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
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
CaO, Mg, MgO
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
13-4
1
7
👆🏻
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Splintery
Streak
Black
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Greasy
Dull
Compressive Strength
225.00 N/mm230.00 N/mm2
0.15
450
👆🏻
Cleavage
Perfect
Slaty
Toughness
1
1.2
Specific Gravity
2.862.65-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm32.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K0.76 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
China, India, Turkey
Africa
Egypt, Ethiopia, Ghana, South Africa, Western Africa
-
Europe
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Others
-
Arctic
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Brazil
Deposits in Oceania Continent
Australia
Central Australia, New Zealand, Queensland
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