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
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Origin
New Zealand
Germany
Discoverer
Unknown
Van Tooren
Etymology
From German which means hornstone
From Greek tephra, ashes from Indo-European base, to burn
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Granular, Platy
Aphanitic to Porphyritic
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Appearance
Dull
Vesicular
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Production of Lime, Soil Conditioner
Types
Biotite hornfels
Not Available
Features
Smooth to touch
Host Rock for Lead
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
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.
Tephrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Andalusite
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Fe, Mg
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
Not Applicable
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
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Uneven
Streak
Unknown
Bluish Black
Porosity
Highly Porous
Very Less Porous
Luster
Shiny
Subvitreous to Dull
Cleavage
Perfect
Crenulation and Pervasive
Toughness
Not Yet Found
2.4
Specific Gravity
3.4-3.9
2.86
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
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
Namibia, Uganda
Europe
United Kingdom
Germany, Hungary, Italy, Portugal, Spain
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Bolivia, Brazil, Colombia, Ecuador
Not Yet Found
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
New Zealand, Western Australia
Hornfels vs Tephrite 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 Tephrite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Tephrite. Learn more about Hornfels vs Tephrite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Tephrite include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Hornfels and Tephrite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Tephrite include Landscaping.
More about Hornfels and Tephrite
Here you can know more about Hornfels and Tephrite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Tephrite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Tephrite includes Alkali feldspar, Nepheline, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Tephrite, 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, Tephrite is available in black, brown, colourless, green, grey, white colors. Appearance of Hornfels is Dull and that of Tephrite is Vesicular. Properties of rock is another aspect for Hornfels vs Tephrite. The hardness of Hornfels is 2-3 and that of Tephrite is 6.5. The types of Hornfels are Biotite hornfels whereas types of Tephrite 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 Tephrite is bluish black. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Tephrite 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 Tephrite is heat resistant, impact resistant.
