Schist

Mylonite

Schist and Mylonite

Schist

Mylonite

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Definition

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

Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism

History

Origin

New Zealand

Discoverer

Unknown

Etymology

From French schiste, Greek skhistos i.e. split

From Greek mulōn mill + -ite

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Foliated, Platy

Foliated

Color

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

Black to Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered and Shiny

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

for Road Aggregate, Landscaping, Roadstone

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments

Other Uses

Commercial Uses

Used in aquariums, Writing Slates

Creating Artwork, Gemstone, Jewelry

Types

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

Blastomylonites, Ultramylonites and Phyllonites

Features

Easily splits into thin plates, Smooth to touch

Surfaces are often shiny

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.

Composition

Mineral Content

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

Porphyroblasts

Compound Content

CaO, Carbon Dioxide, MgO

Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Properties

Physical Properties

Hardness

3.5-43-4

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Luster

Shiny

Compressive Strength

150.00 N/mm²1.28 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Conchoidal

Toughness

1.5

Specific Gravity

2.5-2.92.97-3.05

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³2.6-4.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K1.50 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant, Water Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Indonesia, Saudi Arabia, South Korea

Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

Eritrea, Ethiopia, Ghana, South Africa, Western Africa

Europe

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

England, Finland, France, Germany, Great Britain, Greece, United Kingdom

Others

Deposits in Western Continents

North America

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

USA

South America

Brazil, Colombia, Guyana

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland

Central Australia, Western Australia

All about Schist and Mylonite Properties

Know all about Schist and Mylonite properties here. All properties of rocks are important as they define the type of rock and its application. Schist and Mylonite belong to Metamorphic Rocks.Texture of Schist is Foliated, Platy whereas that of Mylonite is Foliated. Schist appears Layered and Shiny and Mylonite appears Dull, Banded and Foilated. The luster of Schist and Mylonite is shiny. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas Mylonite is available in black to grey colors. The commercial uses of Schist are used in aquariums, writing slates and that of Mylonite are creating artwork, gemstone, jewelry.