Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
  
Basaltic Trachyandesite is an extrusive igneous rock which is a type of Basalt rock and is formed by the rapid cooling of basaltic lava exposed at or very near the Earth's surface
  
History
  
  
Origin
USA
  
Unknown
  
Discoverer
Unknown
  
Unknown
  
Etymology
From the locality in Essex County, Massachusetts,US
  
From its mineral and compound content and its relation with Basalt and Andesite rock
  
Class
Igneous Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Plutonic
  
Volcanic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Granular
  
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
  
Color
Dark Grey to Black
  
Black, Brown, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
Yes
  
Appearance
Banded
  
Dull and Soft
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Floor Tiles, Homes, Hotels, Kitchens
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing, Whetstones
  
Industry
  
  
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
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
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
  
An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork
  
Types
Not Available
  
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
  
Features
Is one of the oldest rock, Smooth to touch
  
Has High structural resistance against erosion and climate, Very fine grained 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
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
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.
  
Basaltic Trachandesite is a fine-grained, hard rock that forms when bits of lava shoot out of volcanoes.
  
Composition
  
  
Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
  
Olivine, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
  
Contact Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering
  
Biological Weathering
  
Erosion
Yes
  
No
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
  
Not Available
  
Physical Properties
  
  
Hardness
7
  
6
  
Grain Size
Fine Grained
  
Fine Grained
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
Black
  
White to Grey
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Not Available
  
Not Available
  
Compressive Strength
Not Available
  
37.50 N/mm
2
  
27
Cleavage
Not Available
  
Not Available
  
Toughness
1.6
  
2.3
  
Specific Gravity
Not Available
  
2.8-3
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.9-3.1 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.84 kJ/Kg K
  
15
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
  
Heat Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
India, Russia
  
India, Russia
  
Africa
South Africa
  
South Africa
  
Europe
Germany, Greece, Italy, Scotland, Turkey
  
Iceland
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, USA
  
South America
Brazil, Colombia, Venezuela
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Queensland
  
Not Yet Found