Definition
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Unknown
Unknown
Etymology
From the locality in Essex County, Massachusetts,US
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Dark Grey to Black
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded
Dull and Soft
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, 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
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Creating Artwork, Gemstone
Types
Intermediate volcanic rock
Cataclastic rock
Features
Is one of the oldest rock, Smooth to touch
Host Rock for Lead
Archaeological Significance
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
-
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion
-
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
Black
Light to dark brown
Porosity
Highly Porous
Less Porous
Specific Gravity
-9999
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
-9999 g/cm3
2.7-2.9 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Russia
South Korea
Africa
South Africa
Western Africa
Europe
Germany, Greece, Italy, Scotland, Turkey
Great Britain, Switzerland
Deposits in Western Continents
North America
Canada, USA
-
South America
Brazil, Colombia, Venezuela
-
Deposits in Oceania Continent
Australia
New Zealand, Queensland
Central Australia, Western Australia
Essexite vs Pseudotachylite 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. Essexite vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Essexite and Properties of Pseudotachylite. Learn more about Essexite vs Pseudotachylite in the next section. The interior uses of Essexite include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Essexite and Pseudotachylite, they have various applications in construction industry. The uses of Essexite in construction industry include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Essexite and Pseudotachylite
Here you can know more about Essexite and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Essexite and Pseudotachylite consists of mineral content and compound content. The mineral content of Essexite includes Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Igneous Rocks. When we have to compare Essexite vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Essexite is available in dark grey to black colors whereas, Pseudotachylite is available in black, brown, green, grey, pink, white colors. Appearance of Essexite is Banded and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Essexite vs Pseudotachylite. Hardness of Essexite and Pseudotachylite is 7. The types of Essexite are Intermediate volcanic rock whereas types of Pseudotachylite are Cataclastic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Essexite is black while that of Pseudotachylite is light to dark brown. The specific heat capacity of Essexite is 0.79 kJ/Kg K and that of Pseudotachylite 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.Essexite is impact resistant, pressure resistant, wear resistant whereas Pseudotachylite is heat resistant.