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
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
Origin
-
Pennines, England
Discoverer
Unknown
J.J. Ferber
Etymology
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
From Grit + Stone
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Clastic, Polished
Earthy
Color
Dark Grey to Black, Pink, Red, White
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Dull
Layered and Foliated
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
Used for flooring, stair treads, borders and window sills.
Construction Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Fire resistant, Used to manufracture paperweights and bookends
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO), Tombstones
Types
Metamorphic rock
Sedimentary rock
Features
Is one of the oldest rock
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
Archaeological Significance
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.
Gritstone is a type of sedimentary rock which was formed on the floors of wide river deltas where the grit deposits were laid down, with every tide or flood dumping another layer of sediment.
Mineral Content
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Calcite, Clay Minerals, Feldspar, Micas, Quartz
Compound Content
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Fine Grained
Coarse Grained
Fracture
Conchoidal to Uneven
Conchoidal
Streak
White to Grey
White
Porosity
Highly Porous
Highly Porous
Luster
Waxy and Dull
Dull
Specific Gravity
2.56-2.68
2.250
Transparency
Opaque
Opaque
Density
2.54-2.66 g/cm3
2.2 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Namibia, Nigeria, South Africa
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Austria, Denmark, Germany, Great Britain, Netherlands, Poland, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
New South Wales, New Zealand, Western Australia
Argillite vs Gritstone Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Argillite vs Gritstone characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Argillite and Properties of Gritstone. Learn more about Argillite vs Gritstone in the next section. The interior uses of Argillite include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Gritstone include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Argillite and Gritstone, they have various applications in construction industry. The uses of Argillite in construction industry include Used for flooring, stair treads, borders and window sills. and that of Gritstone include Construction aggregate, Roadstone.
More about Argillite and Gritstone
Here you can know more about Argillite and Gritstone. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Argillite and Gritstone consists of mineral content and compound content. The mineral content of Argillite includes Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz and mineral content of Gritstone includes Calcite, Clay Minerals, Feldspar, Micas, Quartz. You can also check out the list of all Sedimentary Rocks. When we have to compare Argillite vs Gritstone, the texture, color and appearance plays an important role in determining the type of rock. Argillite is available in dark grey to black, pink, red, white colors whereas, Gritstone is available in beige, black, brown, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. Appearance of Argillite is Rough and Dull and that of Gritstone is Layered and Foliated. Properties of rock is another aspect for Argillite vs Gritstone. The hardness of Argillite is 2-3 and that of Gritstone is 6-7. The types of Argillite are Metamorphic rock whereas types of Gritstone are Sedimentary rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Argillite is white to grey while that of Gritstone is white. The specific heat capacity of Argillite is 0.87 kJ/Kg K and that of Gritstone is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Argillite is heat resistant, impact resistant whereas Gritstone is heat resistant, impact resistant, pressure resistant.