Definition
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
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
Discoverer
Unknown
Unknown
Etymology
From Old French esclate, from esclat (French éclat)
From Latin varius, speckled, variegated
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Foliated
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull and Soft
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture
Commercial Uses
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
Cemetery Markers, Creating Artwork
Types
Not Available
Not Available
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Formation
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
Mineral Content
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Not Applicable
Grain Size
Very fine-grained
Not Applicable
Fracture
Splintery
Conchoidal
Streak
Light to dark brown
White to Grey
Porosity
Less Porous
Less Porous
Luster
Dull
Not Available
Cleavage
Slaty
Not Available
Specific Gravity
2.65-2.8
2.8-3
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.9-3.1 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
India, Russia
Africa
Not Yet Found
South Africa
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Iceland
Others
Arctic
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
Not Yet Found
Slate 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. Slate vs Variolite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Slate and Properties of Variolite. Learn more about Slate vs Variolite in the next section. The interior uses of Slate include Bathrooms, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels, Interior decoration, Kitchens and Stair treads whereas the interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens. Due to some exceptional properties of Slate and Variolite, they have various applications in construction industry. The uses of Slate in construction industry include As dimension stone and that of Variolite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.
More about Slate and Variolite
Here you can know more about Slate and Variolite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Slate and Variolite consists of mineral content and compound content. The mineral content of Slate includes Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon and mineral content of Variolite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Slate vs Variolite, the texture, color and appearance plays an important role in determining the type of rock. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas, Variolite is available in black, brown, light to dark grey colors. Appearance of Slate is Dull and that of Variolite is Dull and Soft. Properties of rock is another aspect for Slate vs Variolite. The hardness of Slate is 3-4 and that of Variolite is 6. The types of Slate 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 Slate is light to dark brown while that of Variolite is white to grey. The specific heat capacity of Slate is 0.76 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.Slate is heat resistant, impact resistant, pressure resistant, wear resistant whereas Variolite is heat resistant, pressure resistant, wear resistant.