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
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
Origin
France
Adak, Aleutian Islands
Discoverer
Unknown
Defant and Drummond
Etymology
From Latin varius, speckled, variegated
From Adak, Aleutian Islands
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Porphyritic
Color
Black, Brown, Light to Dark Grey
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull and Soft
Dull and Soft
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Whetstones
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Commemorative Tablets, Pottery, Used in aquariums
Types
Not Available
Not Available
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained 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.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
Mineral Content
Olivine, Plagioclase, Pyroxene
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Not Applicable
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
Bluish Black
Porosity
Less Porous
Less Porous
Luster
Not Available
Grainy, Pearly and Vitreous
Compressive Strength
Not Available
Cleavage
Not Available
Not Available
Toughness
2.3
Not Available
Specific Gravity
2.8-3
Not Available
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
Not Available
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
India, Russia
Africa
South Africa
Ethiopia, Somalia, South Africa
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
Not Yet Found