Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Essexite which is also known as nepheline monzogabbro, is a dark gray or black holocrystalline plutonic Iigneous Rock
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From the locality in Essex County, Massachusetts,US
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Not Applicable
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Banded
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
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
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone
Cemetery Markers, Commemorative Tablets, Jewelry, Sea Defence, Tombstones
Types
Not Available
Not Available
Features
Host Rock for Lead
Is one of the oldest rock, Smooth to touch
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Not Yet Used
Used
Formation
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.
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.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Aluminium Oxide, Ba, Ca, Cs, Potassium, Rb, Sodium, Sr
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering
Types of Erosion
Not Applicable
Coastal Erosion, Glacier Erosion, Water Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
Light to dark brown
Black
Porosity
Less Porous
Highly Porous
Luster
Vitreous
Not Available
Compressive Strength
Not Available
Cleavage
Irregular
Not Available
Toughness
Not Available
1.6
Specific Gravity
2.46-2.86
Not Available
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
Not Available
Specific Heat Capacity
Not Available
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
South Korea
India, Russia
Africa
Western Africa
South Africa
Europe
Great Britain, Switzerland
Germany, Greece, Italy, Scotland, Turkey
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Not Yet Found
Canada, USA
South America
Not Yet Found
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New Zealand, Queensland
Pseudotachylite 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. Pseudotachylite vs Essexite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pseudotachylite and Properties of Essexite . Learn more about Pseudotachylite vs Essexite in the next section. The interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Essexite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Pseudotachylite and Essexite , they have various applications in construction industry. The uses of Pseudotachylite in construction industry include As dimension stone, Cement manufacture, For road aggregate, Making natural cement and that of Essexite include As dimension stone, Building houses or walls, Cement manufacture, Construction aggregate, For road aggregate.
More about Pseudotachylite and Essexite
Here you can know more about Pseudotachylite and Essexite . The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pseudotachylite and Essexite consists of mineral content and compound content. The mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides and mineral content of Essexite includes Augite, Feldspar, Hornblende, Nepheline, Olivine, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Pseudotachylite vs Essexite , the texture, color and appearance plays an important role in determining the type of rock. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas, Essexite is available in dark grey to black colors. Appearance of Pseudotachylite is Dull and Soft and that of Essexite is Banded. Properties of rock is another aspect for Pseudotachylite vs Essexite . Hardness of Pseudotachylite and Essexite is 7. The types of Pseudotachylite 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 Pseudotachylite is light to dark brown while that of Essexite is black. The specific heat capacity of Pseudotachylite is 0.92 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.Pseudotachylite is heat resistant whereas Essexite is impact resistant, pressure resistant, wear resistant.