Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
  
Lignite is a soft brownish coal which shows traces of plants and is intermediate between bituminous coal and peat
  
History
  
  
Origin
Germany
  
France
  
Discoverer
Van Tooren
  
Unknown
  
Etymology
From Greek tephra, ashes from Indo-European base, to burn
  
From French, Latin lignum wood + -ite1
  
Class
Igneous Rocks
  
Sedimentary Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Soft Rock
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Aphanitic to Porphyritic
  
Amorphous, Glassy
  
Color
Black, Brown, Colourless, Green, Grey, White
  
Black, Brown, Dark Brown, Grey, Light to Dark Grey
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
No
  
Scratch Resistant
Yes
  
No
  
Stain Resistant
No
  
No
  
Wind Resistant
Yes
  
No
  
Acid Resistant
No
  
No
  
Appearance
Vesicular
  
Veined or Pebbled
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Not Yet Used
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
  
Not Yet Used
  
Other Architectural Uses
Curbing
  
Not Yet Used
  
Industry
  
  
Construction Industry
Landscaping
  
for Road Aggregate, Steel Production
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Sculpture
  
Not Yet Used
  
Other Uses
  
  
Commercial Uses
Production of Lime, Soil Conditioner
  
Electricity Generation
  
Types
Not Available
  
Xyloid Lignite or Fossil Wood and Compact Lignite or Perfect Lignite
  
Features
Host Rock for Lead
  
Generally rough to touch, Helps in production of Heat and Electricity, Used as fossil fuel
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Not Yet Used
  
Fossils
Absent
  
Present
  
Formation
Tephrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
  
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.
  
Composition
  
  
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
  
Not Available
  
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
  
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur
  
Transformation
  
  
Metamorphism
Yes
  
No
  
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Not Applicable
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
  
Chemical Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
6.5
  
1
  
Grain Size
Medium to Fine Coarse Grained
  
Medium to Fine Coarse Grained
  
Fracture
Uneven
  
Conchoidal
  
Streak
Bluish Black
  
Black
  
Porosity
Very Less Porous
  
Highly Porous
  
Luster
Subvitreous to Dull
  
Dull to Vitreous to Submetallic
  
Compressive Strength
90.00 N/mm
2
  
22
Not Available
  
Cleavage
Crenulation and Pervasive
  
Non-Existent
  
Toughness
2.4
  
Not Available
  
Specific Gravity
2.86
  
1.1-1.4
  
Transparency
Opaque
  
Opaque
  
Density
2.8-2.9 g/cm3
  
800-801 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
1.26 kJ/Kg K
  
5
Resistance
Heat Resistant, Impact Resistant
  
Heat Resistant
  
Deposits in Eastern Continents
  
  
Asia
Not Yet Found
  
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam
  
Africa
Namibia, Uganda
  
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania
  
Europe
Germany, Hungary, Italy, Portugal, Spain
  
Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
USA
  
Canada, Mexico, USA
  
South America
Not Yet Found
  
Brazil, Chile, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
New Zealand, Western Australia
  
New South Wales, Queensland, Victoria