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Minette and Hornfels


Hornfels and Minette


Definition

Definition
Minette is a variety of Lamprophyre and is porphyritic alkaline igneous rock which is mainly dominated by biotite and potassic feldspar  
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
-  
New Zealand  

Discoverer
Unknown  
Unknown  

Etymology
From French mine ore, mine + ette  
From German which means hornstone  

Class
Igneous Rocks  
Metamorphic Rocks  

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

Family
  
  

Group
Plutonic  
-  

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

Texture

Texture
Porphyritic  
Granular, Platy  

Color
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey  
Brown, Dark Greenish - Grey, Green, Reddish Brown  

Maintenance
Less  
Less  

Durability
Durable  
Durable  

Water Resistant
Yes  
Yes  

Scratch Resistant
Yes  
No  

Stain Resistant
Yes  
No  

Wind Resistant
No  
No  

Acid Resistant
No  
No  

Appearance
Dull, Banded and Foilated  
Dull  

Uses

Architecture
  
  

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

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

Other Architectural Uses
Curbing  
Curbing  

Industry
  
  

Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories  
for Road Aggregate, Roadstone  

Medical Industry
Taken as a Supplement for Calcium or Magnesium  
-  

Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines  
Artifacts, Monuments  

Other Uses
  
  

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

Types

Types
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite  
Biotite hornfels  

Features
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny  
Smooth to touch  

Archaeological Significance
  
  

Monuments
-  
-  

Famous Monuments
-  
-  

Sculpture
-  
-  

Famous Sculptures
-  
-  

Pictographs
-  
-  

Petroglyphs
-  
-  

Figurines
-  
-  

Fossils
Absent  
Absent  

Formation

Formation
Minette formation takes place deep beneath the Earth’s surface at around 150 to 450 kms, and are erupted rapidly and violently.  
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
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene  
Andalusite  

Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide  
Fe, Mg  

Transformation
  
  

Metamorphism
Yes  
No  

Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism  
-  

Weathering
Yes  
Yes  

Types of Weathering
Biological Weathering, Chemical Weathering  
Biological Weathering  

Erosion
Yes  
Yes  

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

Properties

Physical Properties
  
  

Hardness
5-6  
2-3  

Grain Size
Fine to Coarse Grained  
Fine Grained  

Fracture
Conchoidal  
Conchoidal  

Streak
White  
-  

Porosity
Very Less Porous  
Highly Porous  

Luster
Subvitreous to Dull  
Shiny  

Compressive Strength
150.00 N/mm2  
22
5.80 N/mm2  
99+

Cleavage
Conchoidal  
Perfect  

Toughness
-  
-  

Specific Gravity
2.86-2.87  
3.4-3.9  

Transparency
Translucent to Opaque  
Opaque  

Density
2.95-2.96 g/cm3  
0.25-0.30 g/cm3  

Thermal Properties
  
  

Specific Heat Capacity
0.79 kJ/Kg K  
17
0.84 kJ/Kg K  
15

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

Reserves

Deposits in Eastern Continents
  
  

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

Africa
Angola, Botswana, Cameroon, Ethiopia, South Africa  
Cameroon, East Africa, Tanzania, Western Africa  

Europe
England, Hungary, Iceland, United Kingdom  
United Kingdom  

Others
Antarctica, Greenland  
-  

Deposits in Western Continents
  
  

North America
Canada, Mexico, USA  
Canada, USA  

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

Deposits in Oceania Continent
  
  

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

Summary >>
<< Reserves

All about Minette and Hornfels Properties

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

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