Schist

Argillite

Schist and Argillite

Schist

Argillite

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Definition

Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation

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

Unknown

Etymology

From French schiste, Greek skhistos i.e. split

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

Class

Metamorphic Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Foliated, Platy

Clastic, Polished

Color

Black, Blue, Brown, Dark Brown, Green, Grey, Silver

Dark Grey to Black, Pink, Red, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered and Shiny

Rough and Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, Garden Decoration, Office Buildings

Other Architectural Uses

Curbing, Whetstones

Industry

Construction Industry

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

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

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Used in aquariums, Writing Slates

Fire resistant, Used to manufracture paperweights and bookends

Types

Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.

Metamorphic rock

Features

Easily splits into thin plates, Smooth to touch

Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

Formation

Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.

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

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

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

Compound Content

CaO, Carbon Dioxide, MgO

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

3.5-42-3

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Conchoidal to Uneven

Streak

White

White to Grey

Porosity

Highly Porous

Luster

Shiny

Waxy and Dull

Compressive Strength

150.00 N/mm²-

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.5

2.6

Specific Gravity

2.5-2.92.56-2.68

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³2.54-2.66 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K0.87 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant, Water Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Bangladesh, China, India, Russia

Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Europe

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

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

Others

Deposits in Western Continents

North America

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

USA

South America

Brazil, Colombia, Guyana

Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland

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

All about Schist and Argillite Properties

Know all about Schist and Argillite properties here. All properties of rocks are important as they define the type of rock and its application. Schist belongs to Metamorphic Rocks while Argillite belongs to Sedimentary Rocks.Texture of Schist is Foliated, Platy whereas that of Argillite is Clastic, Polished. Schist appears Layered and Shiny and Argillite appears Rough and Dull. The luster of Schist is shiny while that of Argillite is waxy and dull. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas Argillite is available in dark grey to black, pink, red, white colors. The commercial uses of Schist are used in aquariums, writing slates and that of Argillite are fire resistant, used to manufracture paperweights and bookends.