Argillite

Pseudotachylite

Argillite and Pseudotachylite

Argillite

Add ⊕

Definition

Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate

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 Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite

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

Class

Sedimentary Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic, Polished

Quench

Color

Dark Grey to Black, Pink, Red, White

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Dull

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, Garden Decoration, Office Buildings

As Building Stone, As Facing Stone, Garden Decoration

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

Used for flooring, stair treads, borders and window sills.

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

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments

Other Uses

Commercial Uses

Fire resistant, Used to manufracture paperweights and bookends

Creating Artwork, Gemstone

Types

Metamorphic rock

Cataclastic rock

Features

Is one of the oldest rock

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.

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

Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Compound Content

Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

2-37

1 7

👆🏻

Grain Size

Fine Grained

Very fine-grained

Fracture

Conchoidal to Uneven

Uneven

Streak

White to Grey

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Waxy and Dull

Vitreous

Compressive Strength

-60.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.6

Specific Gravity

2.56-2.682.46-2.86

0 8.4

👆🏻

Transparency

Opaque

Transparent to Translucent

Density

2.54-2.66 g/cm³2.7-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.87 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, China, India, Russia

South Korea

Africa

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Western Africa

Europe

Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland

Great Britain, Switzerland

Others

Deposits in Western Continents

North America

USA

South America

Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Victoria, Western Australia

Central Australia, Western Australia

All about Argillite and Pseudotachylite Properties

Know all about Argillite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Argillite belongs to Sedimentary Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Argillite is Clastic, Polished whereas that of Pseudotachylite is Quench. Argillite appears Rough and Dull and Pseudotachylite appears Dull and Soft. The luster of Argillite is waxy and dull while that of Pseudotachylite is vitreous. Argillite is available in dark grey to black, pink, red, white colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Argillite are fire resistant, used to manufracture paperweights and bookends and that of Pseudotachylite are creating artwork, gemstone.