Phyllite

Pseudotachylite

Phyllite and Pseudotachylite

Phyllite

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Definition

Phyllite is a fine-grained metamorphic rock with a well-developed laminar structure, and is intermediate between slate and schist rocks

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 Greek phullon leaf + -ite1

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

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Soft 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

Phyllitic Sheen, Slaty

Quench

Color

Black to Grey, Light Greenish Grey

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Crinkled or Wavy

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar, Roadstone

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

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts, Monuments

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork, Writing Slates

Creating Artwork, Gemstone

Types

Phyllite

Cataclastic rock

Features

Easily splits into thin plates, Is one of the oldest rock, Surfaces are often shiny

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Phyllite is a metamorphic rock which is formed by regional metamorphism of argillaceous sediments since their cleavage arose due to deviatoric stress.

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

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

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, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

1-27

1 7

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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

Phyllitic

Vitreous

Compressive Strength

50.00 N/mm²60.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

1.2

Specific Gravity

2.72-2.732.46-2.86

0 8.4

👆🏻

Transparency

Opaque

Transparent to Translucent

Density

2.18-3.3 g/cm³2.7-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.79 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat 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 Phyllite and Pseudotachylite Properties

Know all about Phyllite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Phyllite and Pseudotachylite belong to Metamorphic Rocks.Texture of Phyllite is Phyllitic Sheen, Slaty whereas that of Pseudotachylite is Quench. Phyllite appears Crinkled or Wavy and Pseudotachylite appears Dull and Soft. The luster of Phyllite is phyllitic while that of Pseudotachylite is vitreous. Phyllite is available in black to grey, light greenish grey colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Phyllite are cemetery markers, commemorative tablets, creating artwork, writing slates and that of Pseudotachylite are creating artwork, gemstone.