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.
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
Group
Not Applicable
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Granular, Platy
Phaneritic
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Brown, Light to Dark Grey, White
Durability
Durable
Durable
Appearance
Dull
Banded and Foilated
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
Construction Industry
for Road Aggregate, Roadstone
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
Not Available
Not Available
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork
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
Not Available
Not Applicable
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Used
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.
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
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
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
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
Not Available
Cleavage
Perfect
Not Available
Toughness
Not Available
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
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Not Available
Africa
Cameroon, East Africa, Tanzania, Western Africa
Egypt
Europe
United Kingdom
Finland, Germany, Italy, Romania, Sweden, Turkey
Others
Not Available
Not Available
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
Hornfels vs Trondhjemite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Hornfels vs Trondhjemite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Trondhjemite. Learn more about Hornfels vs Trondhjemite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Trondhjemite include Decorative aggregates, Entryways, Flooring, Homes and Interior decoration. Due to some exceptional properties of Hornfels and Trondhjemite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Trondhjemite include As dimension stone, Cement manufacture, Cobblestones, Construction aggregate, For road aggregate.
More about Hornfels and Trondhjemite
Here you can know more about Hornfels and Trondhjemite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Trondhjemite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Trondhjemite includes Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Trondhjemite, the texture, color and appearance plays an important role in determining the type of rock. 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. Appearance of Hornfels is Dull and that of Trondhjemite is Banded and Foilated. Properties of rock is another aspect for Hornfels vs Trondhjemite. The hardness of Hornfels is 2-3 and that of Trondhjemite is 6-7. The types of Hornfels are Biotite hornfels whereas types of Trondhjemite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is unknown while that of Trondhjemite is bluish black. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Trondhjemite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Hornfels is heat resistant, impact resistant, pressure resistant whereas Trondhjemite is heat resistant, pressure resistant, wear resistant.
