Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Shoshonite is a basaltic rock, properly a potassic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass
Origin
Germany
Wyoming,USA
Discoverer
Van Tooren
Iddings
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From the place of origin called Shoshone riverin Wyoming
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Porphyritic
Color
Black, Brown, Green, Grey, White
Brown- Black, Dark Brown
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Dull
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Sculpture
Sculpture
Commercial Uses
Production of Lime, Soil Conditioner
Cemetery Markers, Creating Artwork
Types
Igneous rock
Intermediate volcanic rock
Features
Host Rock for Lead
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
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.
Shoshonite 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
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Pyroxene
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, Iron(III) Oxide, Potassium Oxide, Sodium Oxide, Titanium Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
Medium to Fine Coarse Grained
Streak
Bluish Black
White to Grey
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Dull
Cleavage
Crenulation and Pervasive
-
Specific Gravity
2.86
2.98
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.9-3 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Africa
Namibia, Uganda
South Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
Iceland
Deposits in Western Continents
North America
USA
Canada, USA
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
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