Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Origin
Germany
North America
Discoverer
Van Tooren
Theodor von Gümbel
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Andes mountains, where it is found in abundance
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Aphanitic to Porphyritic
Color
Black, Brown, Green, Grey, White
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Dull and Soft
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
Cobblestones, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Production of Lime, Soil Conditioner
Commemorative Tablets, Creating Artwork
Types
Igneous rock
Icelandite
Features
Host Rock for Lead
Generally rough to touch, High silica content, Is one of the oldest rock
Archaeological Significance
Famous Monuments
-
Middle of the Earth in Ecuador
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.
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Streak
Bluish Black
White
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Vitreous
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.86
2.5-2.8
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.11-2.36 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
India, Indonesia, Japan, Nepal, South Korea
Africa
Namibia, Uganda
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Europe
Germany, Hungary, Italy, Portugal, Spain
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Deposits in Western Continents
North America
USA
Mexico, USA
South America
-
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New South Wales, New Zealand, Western Australia