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
  
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
  
History
  
  
Origin
France
  
USA
  
Discoverer
Unknown
  
Unknown
  
Etymology
From Latin varius, speckled, variegated
  
From the locality in Essex County, Massachusetts,US
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Volcanic
  
Plutonic
  
Other Categories
Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
  
Granular
  
Color
Black, Brown, Light to Dark Grey
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
No
  
Yes
  
Acid Resistant
Yes
  
No
  
Appearance
Dull and Soft
  
Banded
  
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, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
  
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
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
  
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
  
Types
Not Available
  
Not Available
  
Features
Has High structural resistance against erosion and climate, Very fine grained rock
  
Is one of the oldest rock, Smooth to touch
  
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
  
Not Used
  
Petroglyphs
Used
  
Not 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.
  
Essexite is a type of igneous rock, which is usually dark grey to black plutonic rock. For the formation of essexite, suitable magma with exact composition of K, Ba, Rb, Cs, Sr should be produced.
  
Composition
  
  
Mineral Content
Olivine, Plagioclase, Pyroxene
  
Augite, Feldspar, Hornblende, Nepheline, 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, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Coastal Erosion, Glacier Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
6
  
7
  
Grain Size
Not Applicable
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White to Grey
  
Black
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Not Available
  
Not Available
  
Compressive Strength
37.50 N/mm
2
  
27
Not Available
  
Cleavage
Not Available
  
Not Available
  
Toughness
2.3
  
1.6
  
Specific Gravity
2.8-3
  
Not Available
  
Transparency
Opaque
  
Opaque
  
Density
2.9-3.1 g/cm3
  
Not Available
  
Thermal Properties
  
  
Specific Heat Capacity
0.84 kJ/Kg K
  
15
Not Available
  
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
  
Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
India, Russia
  
Africa
South Africa
  
South Africa
  
Europe
Iceland
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil
  
Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Not Yet Found
  
New Zealand, Queensland
  
Variolite vs Essexite 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 Essexite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Variolite and Properties of Essexite . Learn more about Variolite vs Essexite in the next section. The interior uses of Variolite include Floor tiles, Flooring, Homes, Hotels and Kitchens whereas the interior uses of Essexite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Variolite and Essexite , 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 Essexite include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Variolite and Essexite
Here you can know more about Variolite and Essexite . The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Variolite and Essexite consists of mineral content and compound content. The mineral content of Variolite includes Olivine, Plagioclase, Pyroxene and mineral content of Essexite includes Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Variolite vs Essexite , 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, Essexite is available in dark grey to black colors. Appearance of Variolite is Dull and Soft and that of Essexite is Banded. Properties of rock is another aspect for Variolite vs Essexite . The hardness of Variolite is 6 and that of Essexite is 7. The types of Variolite are Not Available whereas types of Essexite 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 Essexite is black. The specific heat capacity of Variolite is 0.84 kJ/Kg K and that of Essexite is Not Available. 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 Essexite is impact resistant, pressure resistant, wear resistant.