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
  
Rhomb-porphyry is a porphyritic igneous rock with abundant wedge or lens shaped anorthoclase or feldspar phenocrysts
  
History
  
  
Origin
France
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Latin varius, speckled, variegated
  
From Latin term that means purple
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Volcanic
  
Volcanic
  
Other Categories
Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
  
Aphanitic to Porphyritic
  
Color
Black, Brown, Light to Dark Grey
  
Black, Brown, Colourless, Green, Grey, Pink, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
Yes
  
No
  
Appearance
Dull and Soft
  
Rough
  
Architecture
  
  
Interior Uses
Floor Tiles, Flooring, Homes, Hotels, Kitchens
  
Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
Garden Decoration, Office Buildings
  
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments, Sculpture
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Creating Artwork
  
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Metallurgical Flux, Soil Conditioner, Source of Magnesia (MgO)
  
Types
Not Available
  
Not Available
  
Features
Has High structural resistance against erosion and climate, Very fine grained rock
  
Host Rock for Lead
  
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
Used
  
Used
  
Petroglyphs
Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Absent
  
Absent
  
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.
  
Rhomb-porphyry is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Alkali feldspar, Biotite, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
CaO, Cl, MgO
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6
  
5-5.5
  
Grain Size
Not Applicable
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White to Grey
  
White
  
Porosity
Less Porous
  
Very Less Porous
  
Luster
Not Available
  
Subvitreous to Dull
  
Compressive Strength
37.50 N/mm2
  
27
310.00 N/mm2
  
2
Cleavage
Not Available
  
Perfect
  
Toughness
2.3
  
2.7
  
Specific Gravity
2.8-3
  
2.86
  
Transparency
Opaque
  
Translucent
  
Density
2.9-3.1 g/cm3
  
2.8-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.84 kJ/Kg K
  
15
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Pressure Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Not Yet Found
  
Africa
South Africa
  
Not Yet Found
  
Europe
Iceland
  
Bulgaria
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Brazil
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
Not Yet Found
  
Variolite vs Rhomb Porphyry 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 Rhomb Porphyry characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Rhomb Porphyry. Learn more about Variolite vs Rhomb Porphyry in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Rhomb Porphyry include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Variolite and Rhomb Porphyry, 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 Rhomb Porphyry include As a flux in the production of steel and pig iron, As a sintering agent in steel industry to process iron ore, As dimension stone, Cement manufacture, For road aggregate, Making natural cement, Manufacture of magnesium and dolomite refractories.
More about Variolite and Rhomb Porphyry
Here you can know more about Variolite and Rhomb Porphyry. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Rhomb Porphyry consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Rhomb Porphyry includes Alkali feldspar, Biotite, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Rhomb Porphyry, 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, Rhomb Porphyry is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Variolite is Dull and Soft and that of Rhomb Porphyry is Rough. Properties of rock is another aspect for Variolite vs Rhomb Porphyry. The hardness of Variolite is 6 and that of Rhomb Porphyry is 5-5.5. The types of Variolite are Not Available whereas types of Rhomb Porphyry are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Variolite is white to grey while that of Rhomb Porphyry is white. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Rhomb Porphyry is 0.92 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 Rhomb Porphyry is heat resistant, pressure resistant.