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
  
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
  
History
  
  
Origin
Unknown
  
France
  
Discoverer
Unknown
  
Unknown
  
Etymology
From the English mud and stone, from low German mudde and stainaz
  
From Latin varius, speckled, variegated
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Soft Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Opaque Rock
  
Texture
Clastic
  
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
  
Color
Black, Blue, Brown, Green, Grey, Orange, Red, White, Yellow
  
Black, Brown, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
No
  
Yes
  
Stain Resistant
No
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Rough and Dull
  
Dull and Soft
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Floor Tiles, Interior Decoration
  
Floor Tiles, Flooring, Homes, Hotels, Kitchens
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Roof Tiles
  
Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
  
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Pottery
  
Cemetery Markers, Creating Artwork
  
Types
Marl, Shale and Argillite
  
Not Available
  
Features
Available in Lots of Colors and Patterns, Smooth to touch, Very fine grained rock
  
Has High structural resistance against erosion and climate, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Absent
  
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.
  
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
  
Composition
  
  
Mineral Content
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
  
Olivine, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
No
  
Types of Erosion
Chemical Erosion, Sea Erosion
  
Not Applicable
  
Physical Properties
  
  
Hardness
2-3
  
6
  
Grain Size
Very fine-grained
  
Not Applicable
  
Fracture
Not Available
  
Conchoidal
  
Streak
White
  
White to Grey
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Not Available
  
Compressive Strength
Not Available
  
37.50 N/mm
2
  
27
Cleavage
Perfect
  
Not Available
  
Toughness
2.6
  
2.3
  
Specific Gravity
2.2-2.8
  
2.8-3
  
Transparency
Opaque
  
Opaque
  
Density
2.4-2.8 g/cm3
  
2.9-3.1 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.39 kJ/Kg K
  
23
0.84 kJ/Kg K
  
15
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
Bangladesh, China, India, Russia
  
India, Russia
  
Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
  
South Africa
  
Europe
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
  
Iceland
  
Others
Not Yet Found
  
Not Yet Found
  
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
  
Not Yet Found
  
Mudstone vs Variolite 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. Mudstone vs Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Mudstone and Properties of Variolite. Learn more about Mudstone vs Variolite in the next section. The interior uses of Mudstone include Decorative aggregates, Entryways, Floor tiles and Interior decoration whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Mudstone and Variolite, they have various applications in construction industry. The uses of Mudstone in construction industry include Cement manufacture, Construction aggregate, For road aggregate, Making natural cement, Raw material for the manufacture of mortar and that of Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Mudstone and Variolite
Here you can know more about Mudstone and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Mudstone and Variolite consists of mineral content and compound content. The mineral content of Mudstone includes Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz and mineral content of Variolite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Sedimentary Rocks. When we have to compare Mudstone vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Mudstone is available in black, blue, brown, green, grey, orange, red, white, yellow colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Mudstone is Rough and Dull and that of Variolite is Dull and Soft. Properties of rock is another aspect for Mudstone vs Variolite. The hardness of Mudstone is 2-3 and that of Variolite is 6. The types of Mudstone are Marl, Shale and Argillite whereas types of Variolite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Mudstone is white while that of Variolite is white to grey. The specific heat capacity of Mudstone is 0.39 kJ/Kg K and that of Variolite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Mudstone is heat resistant, impact resistant whereas Variolite is heat resistant, pressure resistant, wear resistant.