Definition
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Discoverer
Unknown
Unknown
Etymology
From French, Latin lignum wood + -ite1
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
for Road Aggregate, Steel Production
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Antiquity Uses
-
Artifacts, Monuments
Commercial Uses
Electricity Generation
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Generally rough to touch, 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 formation takes place due to accumulation of plant debris in a swamp environment. The Coal formation process continues, as peat turns into lignite brown or black coal at increasing heat and pressure.
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
-
Quartz, Silicon
Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
Silicon Dioxide
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Porosity
Highly 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
800-801 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 Lignite and Chert Properties
Know all about Lignite and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Lignite and Chert belong to Sedimentary Rocks.Texture of Lignite is Amorphous, Glassy whereas that of Chert is Banded, Rough. Lignite appears Veined or Pebbled and Chert appears Glassy or Pearly. The luster of Lignite is dull to vitreous to submetallic while that of Chert is waxy and dull. Lignite 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 Lignite are electricity generation and that of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.