Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
  
Boninite is a mafic extrusive rock which is high in magnesium and silica content, formed in fore-arc environments, typically during the early stages of subduction
  
History
  
  
Origin
USA
  
Japan
  
Discoverer
Unknown
  
Unknown
  
Etymology
From the locality in Essex County, Massachusetts,US
  
From its occurrence in the Izu-Bonin arc south of Japan
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Granular
  
Aphanitic to Porphyritic
  
Color
Dark Grey to Black
  
Bluish - Grey, Brown, Colourless, Green, Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Banded
  
Dull and Soft
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Homes, Kitchens
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Not Yet Used
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
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, Small Figurines
  
Artifacts
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
  
An Oil and Gas Reservoir, Cemetery Markers, Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
  
Types
Not Available
  
Not Available
  
Features
Is one of the oldest rock, Smooth to touch
  
Available in Lots of Colors and Patterns, High Mg content, Is one of the oldest rock
  
Archaeological Significance
  
  
Monuments
Used
  
Not Yet Used
  
Famous Monuments
Data Not Available
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
Formation
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.
  
Boninite is a type of Igneous rock which is formed through the cooling and solidification of lava or existing rocks.
  
Composition
  
  
Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
  
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite
  
Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
  
Silicon Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
  
Chemical Erosion, Coastal Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
7
  
7
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Uneven
  
Streak
Black
  
White
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Not Available
  
Vitreous
  
Cleavage
Not Available
  
Not Available
  
Toughness
1.6
  
1.1
  
Specific Gravity
Not Available
  
2.5-2.8
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
Not Available
  
Thermal Properties
  
  
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
Not Available
  
Africa
South Africa
  
South Africa
  
Europe
Germany, Greece, Italy, Scotland, Turkey
  
England, Finland, United Kingdom
  
Others
Greenland
  
Antarctica, Greenland
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Brazil, Colombia, Venezuela
  
Colombia, Uruguay
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Queensland
  
New Zealand, Western Australia