Definition
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
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
History
Origin
-
USA, Australia
Discoverer
Unknown
Tornebohm
Etymology
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Family
Group
-
-
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic, Polished
Earthy, Mud-rich, Rough
Color
Dark Grey to Black, Pink, Red, White
Black, Brown, Green, Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Dull
Dull
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing, Whetstones
Curbing
Industry
Construction Industry
Used for flooring, stair treads, borders and window sills.
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
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Other Uses
Commercial Uses
Fire resistant, Used to manufracture paperweights and bookends
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Metamorphic rock
Endoskarns
Features
Is one of the oldest rock
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Present
Absent
Formation
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.
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.
Composition
Mineral Content
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
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
2-36.5
1
7
👆🏻
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal to Uneven
Irregular
Streak
White to Grey
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Waxy and Dull
Waxy and Dull
Compressive Strength
-70.00 N/mm2
0.15
450
👆🏻
Cleavage
Slaty
Slaty
Toughness
2.6
2.4
Specific Gravity
2.56-2.682.86
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.54-2.66 g/cm32.8-2.9 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.87 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
South Africa, Western Africa
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
United Kingdom
Others
-
-
Deposits in Western Continents
North America
USA
Canada
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
Central Australia, Western Australia