Schist

Skarn

Schist and Skarn

Schist

Skarn

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Definition

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

Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin

History

Origin

USA, Australia

Discoverer

Unknown

Tornebohm

Etymology

From French schiste, Greek skhistos i.e. split

From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness 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

Foliated, Platy

Earthy, Mud-rich, Rough

Color

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

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered and Shiny

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Used in aquariums, Writing Slates

Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)

Types

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

Endoskarns

Features

Easily splits into thin plates, Smooth to touch

Host Rock for Lead, Zinc and Copper Deposits

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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

Composition

Mineral Content

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

Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite

Compound Content

CaO, Carbon Dioxide, MgO

Au, CaO, Carbon Dioxide, Cu, Fe, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

3.5-46.5

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Irregular

Streak

White

Light to dark brown

Porosity

Highly Porous

Less Porous

Luster

Shiny

Waxy and Dull

Compressive Strength

150.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.5

2.4

Specific Gravity

2.5-2.92.86

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact 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

China, India, Russia, Saudi Arabia, South Korea, Sri Lanka

Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

South Africa, Western Africa

Europe

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

United Kingdom

Others

Deposits in Western Continents

North America

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

Canada

South America

Brazil, Colombia, Guyana

Brazil, Colombia, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland

Central Australia, Western Australia

All about Schist and Skarn Properties

Know all about Schist and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Schist and Skarn belong to Metamorphic Rocks.Texture of Schist is Foliated, Platy whereas that of Skarn is Earthy, Mud-rich, Rough. Schist appears Layered and Shiny and Skarn appears Dull. The luster of Schist is shiny while that of Skarn is waxy and dull. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas Skarn is available in black, brown, green, grey, white colors. The commercial uses of Schist are used in aquariums, writing slates and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).