Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers called coal beds
Discoverer
Unknown
John Peter Salley
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From the Old English term col, which has meant mineral of fossilized carbon since the 13th century
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Banded, Rough
Amorphous, Glassy
Color
Black, Brown, Green, Grey, Red, White
Black, Brown, Dark Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Glassy or Pearly
Veined or Pebbled
Interior Uses
Decorative Aggregates, Homes
-
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
-
Other Architectural Uses
Curbing
-
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Peat, Lignite, Sub-Bituminous Coal, Bituminous Coal, Anthracite, Graphite
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Helps in production of Heat and Electricity, Used as fossil fuel
Archaeological Significance
Formation
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.
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.
Mineral Content
Quartz, Silicon
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
Compound Content
Silicon Dioxide
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Erosion
Chemical Erosion
-
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Waxy and Dull
Dull to Vitreous to Submetallic
Specific Gravity
2.5-2.8
1.1-1.4
Transparency
Translucent to Opaque
Opaque
Density
2.7 g/cm3
1100-1400 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
Africa
Kenya, Morocco, South Africa, Tanzania
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Mexico, USA
South America
Bolivia, Brazil
Brazil, Chile, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New South Wales, Queensland, Victoria
All about Chert and Coal Properties
Know all about Chert and Coal properties here. All properties of rocks are important as they define the type of rock and its application. Chert and Coal belong to Sedimentary Rocks.Texture of Chert is Banded, Rough whereas that of Coal is Amorphous, Glassy. Chert appears Glassy or Pearly and Coal appears Veined or Pebbled. The luster of Chert is waxy and dull while that of Coal is dull to vitreous to submetallic. Chert is available in black, brown, green, grey, red, white colors whereas Coal is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Coal are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry.