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
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
Sedimentary Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
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
Durability
Durable
Durable
Appearance
Veined or Pebbled
Glassy or Pearly
Interior Uses
-
Decorative Aggregates, Homes
Exterior Uses
-
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
-
Curbing
Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Antiquity Uses
Artifacts
Artifacts, Monuments
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
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.
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
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
-
Types of Erosion
-
Chemical Erosion
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Less Porous
Highly Porous
Luster
Dull to Vitreous to Submetallic
Waxy and Dull
Specific Gravity
1.1-1.4
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
1100-1400 g/cm3
2.7 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
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
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.