Shale

Argillite

Shale and Argillite

Shale

Argillite

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Definition

Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles

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

History

Origin

Discoverer

Johann Gottlob Lehmann

Unknown

Etymology

From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,

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

Class

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic, Splintery

Clastic, Polished

Color

Black, Brown, Buff, Green, Grey, Red, Yellow

Dark Grey to Black, Pink, Red, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Muddy

Rough and Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Office Buildings

As Building Stone, Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Curbing, Whetstones

Industry

Construction Industry

Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

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

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Creating Artwork, Pottery

Fire resistant, Used to manufracture paperweights and bookends

Types

Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale

Metamorphic rock

Features

Easily splits into thin plates, Generally rough to touch, Very fine grained rock

Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Jantar Mantar in India

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Formation

Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.

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.

Composition

Mineral Content

Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides

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

Compound Content

Ca, Fe, Mg, Silicon Dioxide, Sodium

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

32-3

1 7

👆🏻

Grain Size

Very fine-grained

Fine Grained

Fracture

Conchoidal to Uneven

Streak

White

White to Grey

Porosity

Highly Porous

Luster

Dull

Waxy and Dull

Compressive Strength

95.00 N/mm²-

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.6

Specific Gravity

2.2-2.82.56-2.68

0 8.4

👆🏻

Transparency

Opaque

Density

2.4-2.8 g/cm³2.54-2.66 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.39 kJ/Kg K0.87 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, China, India, Russia

Africa

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Europe

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

All about Shale and Argillite Properties

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