Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
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
Origin
Germany
New Zealand
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From German which means hornstone
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Group
Volcanic
Not Applicable
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Granular, Platy
Color
Black, Brown, Colourless, Green, Grey, White
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Appearance
Vesicular
Dull
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
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
for Road Aggregate, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments
Commercial Uses
Production of Lime, Soil Conditioner
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Not Available
Biotite hornfels
Features
Host Rock for Lead
Smooth to touch
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Used
Not Yet Used
Formation
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.
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.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Andalusite
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Fe, Mg
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
Unknown
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Shiny
Cleavage
Crenulation and Pervasive
Perfect
Toughness
2.4
Not Yet Found
Specific Gravity
2.86
3.4-3.9
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
Namibia, Uganda
Cameroon, East Africa, Tanzania, Western Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Not Yet Found
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, New Zealand, Queensland, Western Australia
All about Tephrite and Hornfels Properties
Know all about Tephrite and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite belongs to Igneous Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Hornfels is Granular, Platy. Tephrite appears Vesicular and Hornfels appears Dull. The luster of Tephrite is subvitreous to dull while that of Hornfels is shiny. Tephrite is available in black, brown, colourless, green, grey, white colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.