Greenschist

Pseudotachylite

Greenschist and Pseudotachylite

Greenschist

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Definition

Greenschist is a metamorphic rock that is formed under lowest temperatures and pressures and is usually produced by regional metamorphism

Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.

History

Origin

USA

Discoverer

Unknown

Etymology

From minerals such as chlorite, serpentine, and epidote, and platy minerals such as muscovite and platy serpentine which are green in color

From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Other Categories

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Foliated, Platy

Quench

Color

Dark Greenish - Grey, Green

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered and Shiny

Dull and Soft

Uses

Architecture

Interior Uses

Bathrooms, Countertops, Decorative Aggregates, Entryways, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Building houses or walls, Cement Manufacture, Cutting Tool, for Road Aggregate, Roadstone

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments

Other Uses

Commercial Uses

Blackboards, Manufacture of tools, Writing Slates

Creating Artwork, Gemstone

Types

Metamorphic rock

Cataclastic rock

Features

Easily splits into thin plates, Smooth to touch

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Greenschist is medium grade metamorphic rock, formed by the metamorphosis of mudstone or shale, or some types of igneous rock, when it is subjected to higher temperatures and pressures.

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.

Composition

Mineral Content

Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Serpentine, Sillimanite, Staurolite, Talc

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Compound Content

CaO, Carbon Dioxide, MgO

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion

Properties

Physical Properties

Hardness

3.5-47

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Very fine-grained

Fracture

Conchoidal

Uneven

Streak

White

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Shiny

Vitreous

Compressive Strength

160.00 N/mm²60.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.5

Specific Gravity

2.5-2.92.46-2.86

0 8.4

👆🏻

Transparency

Opaque

Transparent to Translucent

Density

2.8-2.9 g/cm³2.7-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant, Water Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam

South Korea

Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Western Africa

Europe

Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland

Great Britain, Switzerland

Others

Deposits in Western Continents

North America

Canada, Costa Rica, Cuba, Mexico, Panama, USA

South America

Brazil, Colombia, Guyana

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland

Central Australia, Western Australia

All about Greenschist and Pseudotachylite Properties

Know all about Greenschist and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Greenschist and Pseudotachylite belong to Metamorphic Rocks.Texture of Greenschist is Foliated, Platy whereas that of Pseudotachylite is Quench. Greenschist appears Layered and Shiny and Pseudotachylite appears Dull and Soft. The luster of Greenschist is shiny while that of Pseudotachylite is vitreous. Greenschist is available in dark greenish - grey, green colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Greenschist are blackboards, manufacture of tools, writing slates and that of Pseudotachylite are creating artwork, gemstone.