Coal

Skarn

Coal and Skarn

Coal

Skarn

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Definition

Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds

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

USA, Australia

Discoverer

John Peter Salley

Tornebohm

Etymology

From the Old English term col, which has meant mineral of fossilized carbon since the 13th century

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

Class

Sedimentary Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Soft 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

Amorphous, Glassy

Earthy, Mud-rich, Rough

Color

Black, Brown, Dark Brown, Grey, Light to Dark Grey

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Veined or Pebbled

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production

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

Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry

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

Types

Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite

Endoskarns

Features

Helps in production of Heat and Electricity, Used as fossil fuel

Host Rock for Lead, Zinc and Copper Deposits

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

Coal forms from the accumulation of plant debris in a swamp environment which is buried by sediments such as mud or sand and then compacted to form coal.

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

Analcime, Apatite, Barite, Calcite, Chalcopyrite, Chlorite, Chromite, Clausthalite, Clay Minerals, Crandallite Group, Dolomite, Feldspar, Galena, Gypsum, Marcasite, Muscovite or Illite, Pyrite, Quartz, Siderite, Sphalerite, Zircon

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

Compound Content

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Erosion

✔ ✘

Types of Erosion

Properties

Physical Properties

Hardness

1-1.56.5

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Irregular

Streak

Black

Light to dark brown

Porosity

Less Porous

Luster

Dull to Vitreous to Submetallic

Waxy and Dull

Compressive Strength

-70.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.4

Specific Gravity

1.1-1.42.86

0 8.4

👆🏻

Transparency

Opaque

Density

1100-1400 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.32 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam

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

Africa

Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania

South Africa, Western Africa

Europe

Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom

United Kingdom

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada

South America

Brazil, Chile, Colombia, Venezuela

Brazil, Colombia, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, Queensland, Victoria

Central Australia, Western Australia

All about Coal and Skarn Properties

Know all about Coal and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Coal belongs to Sedimentary Rocks while Skarn belongs to Metamorphic Rocks.Texture of Coal is Amorphous, Glassy whereas that of Skarn is Earthy, Mud-rich, Rough. Coal appears Veined or Pebbled and Skarn appears Dull. The luster of Coal is dull to vitreous to submetallic while that of Skarn is waxy and dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Skarn is available in black, brown, green, grey, white colors. The commercial uses of Coal are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).