Definition
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate
History
Origin
USA
-
Discoverer
Unknown
Unknown
Etymology
From 17th century, because of its greasy feel and use like a soap
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Polished
Clastic, Polished
Color
Black, Black to Grey, Green, Grey
Dark Grey to Black, Pink, Red, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Rough and Dull
Architecture
Interior Uses
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Facing Stone, Garden Decoration
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Industry
Construction Industry
Manufacture of Magnesium and Dolomite Refractories
Used for flooring, stair treads, borders and window sills.
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Jewellery, Monuments, Sculpture
Artifacts, Monuments, Sculpture
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)
Fire resistant, Used to manufracture paperweights and bookends
Types
Metamorphic rock
Metamorphic rock
Features
Host Rock for Lead
Is one of the oldest 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
Present
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.
An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.
Composition
Mineral Content
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
CaO, Mg, MgO
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
-
Biological Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Chemical Erosion
Physical Properties
Hardness
12-3
1
7
👆🏻
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal to Uneven
Streak
Black
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Greasy
Waxy and Dull
Compressive Strength
225.00 N/mm2-
0.15
450
👆🏻
Cleavage
Perfect
Slaty
Toughness
1
2.6
Specific Gravity
2.862.56-2.68
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm32.54-2.66 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.88 kJ/Kg K0.87 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Bangladesh, China, India, Russia
Africa
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Others
-
-
Deposits in Western Continents
North America
Canada, USA
USA
South America
Colombia
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, New Zealand, Queensland
New South Wales, New Zealand, Queensland, Victoria, Western Australia