Definition
Gritstone or grit is a hard, coarse-grained, siliceous sandstone
  
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
Pennines, England
  
France
  
Discoverer
J.J. Ferber
  
Unknown
  
Etymology
From Grit + Stone
  
From Latin varius, speckled, variegated
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Opaque Rock
  
Texture
Earthy
  
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
  
Color
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
  
Black, Brown, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Layered and Foliated
  
Dull and Soft
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
  
Floor Tiles, Flooring, Homes, Hotels, Kitchens
  
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
  
Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
Construction Aggregate, Roadstone
  
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO), Tombstones
  
Cemetery Markers, Creating Artwork
  
Types
Not Available
  
Not Available
  
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Very fine grained rock
  
Has High structural resistance against erosion and climate, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Absent
  
Formation
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.
  
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
Calcite, Clay Minerals, Feldspar, Micas, Quartz
  
Olivine, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium 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
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
No
  
Types of Erosion
Chemical Erosion, Coastal Erosion
  
Not Applicable
  
Physical Properties
  
  
Hardness
6-7
  
6
  
Grain Size
Coarse Grained
  
Not Applicable
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White
  
White to Grey
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Not Available
  
Compressive Strength
70.00 N/mm2
  
24
37.50 N/mm2
  
27
Cleavage
Perfect
  
Not Available
  
Toughness
Not Available
  
2.3
  
Specific Gravity
2.250
  
2.8-3
  
Transparency
Opaque
  
Opaque
  
Density
2.2 g/cm3
  
2.9-3.1 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
0.84 kJ/Kg K
  
15
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
India, Russia
  
Africa
Namibia, Nigeria, South Africa
  
South Africa
  
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Poland, Sweden, Switzerland, United Kingdom
  
Iceland
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand, Western Australia
  
Not Yet Found
  
Gritstone 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. Gritstone vs Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gritstone and Properties of Variolite. Learn more about Gritstone vs Variolite in the next section. The interior uses of Gritstone include Countertops, Decorative aggregates, Homes and Interior decoration whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Gritstone and Variolite, they have various applications in construction industry. The uses of Gritstone in construction industry include Construction aggregate, Roadstone and that of Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Gritstone and Variolite
Here you can know more about Gritstone and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gritstone and Variolite consists of mineral content and compound content. The mineral content of Gritstone includes Calcite, Clay Minerals, Feldspar, Micas, 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 Gritstone vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Gritstone is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Gritstone is Layered and Foliated and that of Variolite is Dull and Soft. Properties of rock is another aspect for Gritstone vs Variolite. The hardness of Gritstone is 6-7 and that of Variolite is 6. The types of Gritstone are Not Available 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 Gritstone is white while that of Variolite is white to grey. The specific heat capacity of Gritstone is 0.92 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.Gritstone is heat resistant, impact resistant, pressure resistant whereas Variolite is heat resistant, pressure resistant, wear resistant.