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Anthracite and Hornfels


Hornfels and Anthracite


Definition

Definition
Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster  
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock  

History
  
  

Origin
Pennsylvania, U.S.  
New Zealand  

Discoverer
Unknown  
Unknown  

Etymology
From Greek anthrakites, from anthrax, anthrak meaning coal  
From German which means hornstone  

Class
Metamorphic Rocks  
Metamorphic Rocks  

Sub-Class
Durable Rock, Soft Rock  
Durable Rock, Soft Rock  

Family
  
  

Group
-  
-  

Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock  
Fine Grained Rock, Opaque Rock  

Texture

Texture
Amorphous, Glassy  
Granular, Platy  

Color
Black, Brown, Dark Brown, Grey, Light to Dark Grey  
Brown, Dark Greenish - Grey, Green, Reddish Brown  

Maintenance
Less  
Less  

Durability
Durable  
Durable  

Water Resistant
No  
Yes  

Scratch Resistant
No  
No  

Stain Resistant
No  
No  

Wind Resistant
No  
No  

Acid Resistant
No  
No  

Appearance
Veined or Pebbled  
Dull  

Uses

Architecture
  
  

Interior Uses
-  
Decorative Aggregates, Flooring, Homes, Interior Decoration  

Exterior Uses
-  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone  

Other Architectural Uses
-  
Curbing  

Industry
  
  

Construction Industry
Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production  
for Road Aggregate, Roadstone  

Medical Industry
In Chemical and Pharmaceutical Industry, Manufacture of Aspirins  
-  

Antiquity Uses
-  
Artifacts, Monuments  

Other Uses
  
  

Commercial Uses
Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry  
Cemetery Markers, Commemorative Tablets, Creating Artwork  

Types

Types
Semi-anthracite and Meta-anthracite  
Biotite hornfels  

Features
Helps in production of Heat and Electricity, Used as fossil fuel  
Smooth to touch  

Archaeological Significance
  
  

Monuments
-  
-  

Famous Monuments
-  
-  

Sculpture
-  
-  

Famous Sculptures
-  
-  

Pictographs
-  
-  

Petroglyphs
-  
-  

Figurines
-  
-  

Fossils
Absent  
Absent  

Formation

Formation
Anthracite forms from the accumulation of plant debris in a swamp environment. When plant debris dies and falls into the swamp, the standing water of the swamp protects it from decay.   
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.  

Composition
  
  

Mineral Content
Calcite, Clay, Clay Minerals  
Andalusite  

Compound Content
Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur  
Fe, Mg  

Transformation
  
  

Metamorphism
Yes  
No  

Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Regional Metamorphism  
-  

Weathering
No  
Yes  

Types of Weathering
-  
Biological Weathering  

Erosion
No  
Yes  

Types of Erosion
-  
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion  

Properties

Physical Properties
  
  

Hardness
1-1.5  
2-3  

Grain Size
Medium to Fine Coarse Grained  
Fine Grained  

Fracture
Conchoidal  
Conchoidal  

Streak
Black  
-  

Porosity
Less Porous  
Highly Porous  

Luster
Shiny  
Shiny  

Compressive Strength
-  
5.80 N/mm2  
99+

Cleavage
-  
Perfect  

Toughness
-  
-  

Specific Gravity
1.1-1.4  
3.4-3.9  

Transparency
Opaque  
Opaque  

Density
1.25-2.5 g/cm3  
0.25-0.30 g/cm3  

Thermal Properties
  
  

Specific Heat Capacity
1.32 kJ/Kg K  
4
0.84 kJ/Kg K  
15

Resistance
Heat Resistant, Water Resistant  
Heat Resistant, Impact Resistant, Pressure Resistant  

Reserves

Deposits in Eastern Continents
  
  

Asia
Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam  
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand  

Africa
Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania  
Cameroon, East Africa, Tanzania, Western Africa  

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

Others
-  
-  

Deposits in Western Continents
  
  

North America
Canada, Mexico, USA  
Canada, USA  

South America
Brazil, Chile, Colombia, Venezuela  
Bolivia, Brazil, Colombia, Ecuador  

Deposits in Oceania Continent
  
  

Australia
New South Wales, Queensland, Victoria  
New South Wales, New Zealand, Queensland, Western Australia  

Summary >>
<< Reserves

All about Anthracite and Hornfels Properties

Know all about Anthracite and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Anthracite and Hornfels belong to Metamorphic Rocks.Texture of Anthracite is Amorphous, Glassy whereas that of Hornfels is Granular, Platy. Anthracite appears Veined or Pebbled and Hornfels appears Dull. The luster of Anthracite and Hornfels is shiny. Anthracite is available in black, brown, dark brown, grey, light to dark grey colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Anthracite are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.

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