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Hornfels and Jasperoid


Jasperoid and Hornfels


Definition

Definition
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  
Jasperoid is a rare, peculiar type of metasomatic alteration of rocks  

History
  
  

Origin
New Zealand  
USA  

Discoverer
Unknown  
Unknown  

Etymology
From German which means hornstone  
From silica, the main mineral content of Jasperoid  

Class
Metamorphic Rocks  
Sedimentary Rocks  

Sub-Class
Durable Rock, Soft Rock  
Durable Rock, Medium Hardness Rock  

Family
  
  

Group
-  
-  

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

Texture

Texture
Granular, Platy  
Earthy  

Color
Brown, Dark Greenish - Grey, Green, Reddish Brown  
Black, Brown, Green, Grey, Pink, White  

Maintenance
Less  
Less  

Durability
Durable  
Durable  

Water Resistant
Yes  
Yes  

Scratch Resistant
No  
Yes  

Stain Resistant
No  
Yes  

Wind Resistant
No  
No  

Acid Resistant
No  
No  

Appearance
Dull  
Glassy or Pearly  

Uses

Architecture
  
  

Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration  
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration  

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

Other Architectural Uses
Curbing  
Curbing  

Industry
  
  

Construction Industry
for Road Aggregate, Roadstone  
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock  

Medical Industry
-  
Taken as a Supplement for Calcium or Magnesium  

Antiquity Uses
Artifacts, Monuments  
Artifacts, Jewellery, Monuments, Sculpture  

Other Uses
  
  

Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork  
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)  

Types

Types
Biotite hornfels  
-  

Features
Smooth to touch  
Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits  

Archaeological Significance
  
  

Monuments
-  
-  

Famous Monuments
-  
-  

Sculpture
-  
-  

Famous Sculptures
-  
-  

Pictographs
-  
-  

Petroglyphs
-  
-  

Figurines
-  
-  

Fossils
Absent  
Present  

Formation

Formation
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.  
Jasperoid is a rare and peculiar type of metasomatic alteration of rocks. It is formed by extreme alteration of wall rocks within a shear zone which may occur in sediments, andesites, trachytes and basalts.  

Composition
  
  

Mineral Content
Andalusite  
Clay Minerals, Pyrite, Quartz, Sulfides  

Compound Content
Fe, Mg  
NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO  

Transformation
  
  

Metamorphism
No  
Yes  

Types of Metamorphism
-  
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism  

Weathering
Yes  
No  

Types of Weathering
Biological Weathering  
-  

Erosion
Yes  
No  

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

Properties

Physical Properties
  
  

Hardness
2-3  
3.5-4  

Grain Size
Fine Grained  
Medium to Fine Coarse Grained  

Fracture
Conchoidal  
Conchoidal  

Streak
-  
White  

Porosity
Highly Porous  
Less Porous  

Luster
Shiny  
Vitreous and Pearly  

Compressive Strength
5.80 N/mm2  
99+
140.00 N/mm2  
23

Cleavage
Perfect  
Perfect  

Toughness
-  
1  

Specific Gravity
3.4-3.9  
2.8-3  

Transparency
Opaque  
Transparent to Translucent  

Density
0.25-0.30 g/cm3  
2.8-2.9 g/cm3  

Thermal Properties
  
  

Specific Heat Capacity
0.84 kJ/Kg K  
15
0.92 kJ/Kg K  
10

Resistance
Heat Resistant, Impact Resistant, Pressure Resistant  
Heat Resistant, Pressure Resistant, Wear Resistant  

Reserves

Deposits in Eastern Continents
  
  

Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand  
China, India  

Africa
Cameroon, East Africa, Tanzania, Western Africa  
Morocco, Namibia  

Europe
United Kingdom  
Austria, Italy, Romania, Spain, Switzerland  

Others
-  
-  

Deposits in Western Continents
  
  

North America
Canada, USA  
Mexico, USA  

South America
Bolivia, Brazil, Colombia, Ecuador  
Brazil, Colombia  

Deposits in Oceania Continent
  
  

Australia
New South Wales, New Zealand, Queensland, Western Australia  
New South Wales, Queensland, Yorke Peninsula  

Summary >>
<< Reserves

All about Hornfels and Jasperoid Properties

Know all about Hornfels and Jasperoid properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Jasperoid belongs to Sedimentary Rocks.Texture of Hornfels is Granular, Platy whereas that of Jasperoid is Earthy. Hornfels appears Dull and Jasperoid appears Glassy or Pearly. The luster of Hornfels is shiny while that of Jasperoid is vitreous and pearly. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Jasperoid is available in black, brown, green, grey, pink, white colors. The commercial uses of Hornfels are cemetery markers, commemorative tablets, creating artwork and that of Jasperoid are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).

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