Home
Compare Rocks


Hornfels and Trondhjemite


Trondhjemite 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   
Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.   

History
  
  

Origin
New Zealand   
Tonale, Italy   

Discoverer
Unknown   
Unknown   

Etymology
From German which means hornstone   
Not Available   

Class
Metamorphic Rocks   
Igneous Rocks   

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

Family
  
  

Group
Not Applicable   
Plutonic   

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

Texture

Texture
Granular, Platy   
Phaneritic   

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

Uses

Architecture
  
  

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

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

Other Architectural Uses
Curbing   
Curbing   

Industry
  
  

Construction Industry
for Road Aggregate, Roadstone   
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate   

Medical Industry
Not Yet Used   
Not Yet Used   

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

Other Uses
  
  

Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork   
Cemetery Markers, Creating Artwork   

Types

Types
Biotite hornfels   
Not Available   

Features
Smooth to touch   
Is one of the oldest rock, Typically speckled black and white.   

Archaeological Significance
  
  

Monuments
Used   
Not Yet Used   

Famous Monuments
Data Not Available   
Not Applicable   

Sculpture
Not Yet Used   
Used   

Famous Sculptures
Not Applicable   
Data Not Available   

Pictographs
Used   
Not Used   

Petroglyphs
Used   
Not Used   

Figurines
Not Yet Used   
Used   

Fossils
Absent   
Absent   

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.   
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.   

Composition
  
  

Mineral Content
Andalusite   
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon   

Compound Content
Fe, Mg   
NaCl, CaO, MgO, Silicon Dioxide   

Transformation
  
  

Metamorphism
No   
Yes   

Types of Metamorphism
Not Applicable   
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism   

Weathering
Yes   
Yes   

Types of Weathering
Biological Weathering   
Biological Weathering, Chemical Weathering, Mechanical Weathering   

Erosion
Yes   
Yes   

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

Properties

Physical Properties
  
  

Hardness
2-3   
6-7   

Grain Size
Fine Grained   
Medium to Fine Coarse Grained   

Fracture
Conchoidal   
Conchoidal   

Streak
Unknown   
Bluish Black   

Porosity
Highly Porous   
Very Less Porous   

Luster
Shiny   
Subvitreous to Dull   

Compressive Strength
5.80 N/mm2   
31
Not Available   

Cleavage
Perfect   
Not Available   

Toughness
Not Yet Found   
2.1   

Specific Gravity
3.4-3.9   
2.86-3   

Transparency
Opaque   
Opaque   

Density
0.25-0.30 g/cm3   
2.73 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   
Not Yet Found   

Africa
Cameroon, East Africa, Tanzania, Western Africa   
Egypt   

Europe
United Kingdom   
Finland, Germany, Italy, Romania, Sweden, Turkey   

Others
Not Yet Found   
Not Yet Found   

Deposits in Western Continents
  
  

North America
Canada, USA   
USA   

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

Deposits in Oceania Continent
  
  

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

Summary >>
<< Reserves

All about Hornfels and Trondhjemite Properties

Know all about Hornfels and Trondhjemite properties here. All properties of rocks are important as they define the type of rock and its application. Hornfels belongs to Metamorphic Rocks while Trondhjemite belongs to Igneous Rocks.Texture of Hornfels is Granular, Platy whereas that of Trondhjemite is Phaneritic. Hornfels appears Dull and Trondhjemite appears Banded and Foilated. The luster of Hornfels is shiny while that of Trondhjemite is subvitreous to dull. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas Trondhjemite is available in black, brown, light to dark grey, white colors. The commercial uses of Hornfels and Trondhjemite are cemetery markers, commemorative tablets, creating artwork.

Compare Metamorphic Rocks

Metamorphic Rocks

Metamorphic Rocks

» More Metamorphic Rocks

Compare Metamorphic Rocks

» More Compare Metamorphic Rocks