Coal

Chert

Coal and Chert

Coal

Chert

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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

Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture

History

Origin

USA

Discoverer

John Peter Salley

Unknown

Etymology

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

From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use

Class

Sedimentary 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

Banded, Rough

Color

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

Black, Brown, Green, Grey, Red, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Veined or Pebbled

Glassy or Pearly

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments

Other Uses

Commercial Uses

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

Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms

Types

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

Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter

Features

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

Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

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.

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

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

Quartz, Silicon

Compound Content

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

1-1.56.5-7

1 7

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Grain Size

Medium to Fine Coarse Grained

Very fine-grained

Fracture

Conchoidal

Uneven, Splintery or Conchoidal

Streak

Black

White

Porosity

Less Porous

Highly Porous

Luster

Dull to Vitreous to Submetallic

Waxy and Dull

Compressive Strength

-450.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.5

Specific Gravity

1.1-1.42.5-2.8

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

1100-1400 g/cm³2.7 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.32 kJ/Kg K0.74 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

Africa

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

Kenya, Morocco, South Africa, Tanzania

Europe

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

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

Others

Greenland, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, Mexico, USA

South America

Brazil, Chile, Colombia, Venezuela

Bolivia, Brazil

Deposits in Oceania Continent

Australia

New South Wales, Queensland, Victoria

New South Wales, Queensland, South Australia, Western Australia

All about Coal and Chert Properties

Know all about Coal and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Coal and Chert belong to Sedimentary Rocks.Texture of Coal is Amorphous, Glassy whereas that of Chert is Banded, Rough. Coal appears Veined or Pebbled and Chert appears Glassy or Pearly. The luster of Coal is dull to vitreous to submetallic while that of Chert is waxy and dull. Coal is available in black, brown, dark brown, grey, light to dark grey colors whereas Chert is available in black, brown, green, grey, red, 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 Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.