Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Siltstone can be defined as a fine-grained sedimentary rock which mainly consists of consolidated silt
Discoverer
Unknown
Unknown
Etymology
From the locality in Essex County, Massachusetts,US
From English word silt and stone and from Proto-Indo-European root sal and stainaz
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Plutonic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Dark Grey to Black
Brown, Red, Reddish Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Raw material for the manufacture of mortar, Soil Conditioner
Types
Not Available
Not Available
Features
Is one of the oldest rock, Smooth to touch
Available in Lots of Colors and Patterns, Easily splits into thin plates, Generally rough to touch, High silica content, Very fine grained rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
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.
Siltstone is a type of sedimentary rock which is formed from fine rock particles. As the particles of eroded rock travel along with water, the edges of the rock are worn-out by water into a rounded shape.
Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz, Sand, Silica, Silt
Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Luster
Not Available
Dull
Cleavage
Not Available
Not Available
Specific Gravity
Not Available
2.54-2.73
Transparency
Opaque
Opaque
Density
Not Available
2.6-2.7 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
South Africa
Namibia, Nigeria, South Africa
Europe
Germany, Greece, Italy, Scotland, Turkey
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Colombia, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New South Wales, New Zealand