Definition
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
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
Unknown
Unknown
Etymology
From Latin varius, speckled, variegated
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Group
Volcanic
Not Applicable
Other Categories
Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Clastic, Polished
Color
Black, Brown, Light to Dark Grey
Dark Grey to Black, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Rough and Dull
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Used for flooring, stair treads, borders and window sills.
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Creating Artwork
Fire resistant, Used to manufracture paperweights and bookends
Types
Not Available
Not Available
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Formation
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
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
Olivine, Plagioclase, Pyroxene
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Not Applicable
Chemical Erosion
Grain Size
Not Applicable
Fine Grained
Fracture
Conchoidal
Conchoidal to Uneven
Streak
White to Grey
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Not Available
Waxy and Dull
Compressive Strength
Not Available
Cleavage
Not Available
Slaty
Specific Gravity
2.8-3
2.56-2.68
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
2.54-2.66 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Russia
Bangladesh, China, India, Russia
Africa
South Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Iceland
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, New Zealand, Queensland, Victoria, Western Australia
Variolite vs Argillite 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. Variolite vs Argillite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Argillite. Learn more about Variolite vs Argillite in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Argillite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Variolite and Argillite, they have various applications in construction industry. The uses of Variolite in construction industry include As dimension stone, Cobblestones, Rail track ballast, Roadstone and that of Argillite include Used for flooring, stair treads, borders and window sills..
More about Variolite and Argillite
Here you can know more about Variolite and Argillite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Argillite consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Argillite includes Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Argillite, the texture, color and appearance plays an important role in determining the type of rock. Variolite is available in black, brown, light to dark grey colors whereas, Argillite is available in dark grey to black, pink, red, white colors. Appearance of Variolite is Dull and Soft and that of Argillite is Rough and Dull. Properties of rock is another aspect for Variolite vs Argillite. The hardness of Variolite is 6 and that of Argillite is 2-3. The types of Variolite are Not Available whereas types of Argillite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Variolite and Argillite is white to grey. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Argillite is 0.87 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Variolite is heat resistant, pressure resistant, wear resistant whereas Argillite is heat resistant, impact resistant.