Definition
Mudstone is a fine-grained, dark gray sedimentary rock, which is formed from silt and clay and is similar to shale but has less laminations
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
Discoverer
William Smith
Unknown
Etymology
From the English mud and stone, from low German mudde and stainaz
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Clastic
Clastic, Polished
Color
Black, Blue, Brown, Green, Grey, Orange, Red, White, Yellow
Dark Grey to Black, Pink, Red, White
Durability
Durable
Durable
Appearance
Rough and Dull
Rough and Dull
Interior Uses
Decorative Aggregates, Entryways, Floor Tiles, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Roof Tiles
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Used for flooring, stair treads, borders and window sills.
Antiquity Uses
Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Pottery
Fire resistant, Used to manufracture paperweights and bookends
Types
Marl, Shale and Argillite
Metamorphic rock
Features
Available in Lots of Colors and Patterns, Smooth to touch, Very fine grained rock
Is one of the oldest rock
Archaeological Significance
Formation
Mudstone forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are buried and compacted by overlying sediment hence forming mudstone.
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.
Mineral Content
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Sea Erosion
Chemical Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
-
Conchoidal to Uneven
Streak
White
White to Grey
Porosity
Highly Porous
Highly Porous
Luster
Dull
Waxy and Dull
Specific Gravity
2.2-2.8
2.56-2.68
Transparency
Opaque
Opaque
Density
2.4-2.8 g/cm3
2.54-2.66 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
Bangladesh, China, India, Russia
Bangladesh, China, India, Russia
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
South America
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia