Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Mylonite is a metamorphic rock formed by ductile deformation during intense shearing encountered during folding and faulting, a process termed cataclastic or dynamic metamorphism
Origin
Germany
New Zealand
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Greek mulōn mill + -ite
Class
Igneous Rocks
Metamorphic 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
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Foliated
Color
Black, Brown, Green, Grey, White
Black to Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Landscaping
for Road Aggregate, Landscaping, Roadstone
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments
Commercial Uses
Production of Lime, Soil Conditioner
Creating Artwork, Gemstone, Jewelry
Types
Igneous rock
Blastomylonites, Ultramylonites and Phyllonites
Features
Host Rock for Lead
Surfaces are often shiny
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.
Mylonites are ductilely deformed rocks formed by the accumulation of large shear strain, in ductile fault zones.
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Porphyroblasts
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Aluminium Oxide, Calcium Sulfate, Chromium(III) Oxide, Iron(III) Oxide, Magnesium Carbonate, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact 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, Sea Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Shiny
Cleavage
Crenulation and Pervasive
Conchoidal
Specific Gravity
2.86
2.97-3.05
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.6-4.8 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
-
China, India, Indonesia, Saudi Arabia, South Korea
Africa
Namibia, Uganda
Eritrea, Ethiopia, Ghana, South Africa, Western Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
England, Finland, France, Germany, Great Britain, Greece, United Kingdom
Deposits in Western Continents
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Central Australia, Western Australia