Definition
Anorthosite is a granular igneous rock composed largely of labradorite or plagioclase
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Discoverer
Unknown
Van Tooren
Etymology
From French anorthose plagioclase + -ite1
From Greek tephra, ashes from Indo-European base, to burn
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Foliated, Glassy
Aphanitic to Porphyritic
Color
Black, Bluish - Grey, Brown, Green, Grey, Light Greenish Grey, Pink, White
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Vesicular
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Landscaping
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Sculpture
Commercial Uses
Creating Artwork, Curling
Production of Lime, Soil Conditioner
Types
Proterozoic Anorthosite and Archean Anorthosite
Igneous rock
Features
Generally rough to touch, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Formation
Anorthosite is a phaneritic, intrusive igneous rock which is characterized by a predominance of plagioclase feldspar which is almost 90–100%, and a minimal mafic component.
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
Amphibole, Clinopyroxene, Ilmenite, Magnetite, Olivine, Orthopyroxene
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Compound Content
Ca, CaO, Chromium(III) Oxide, MgO, Sulfur Trioxide
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Grain Size
Coarse Grained
Medium to Fine Coarse Grained
Fracture
Irregular
Uneven
Streak
White
Bluish Black
Porosity
Less Porous
Very Less Porous
Luster
Pearly to Subvitreous
Subvitreous to Dull
Cleavage
-
Crenulation and Pervasive
Specific Gravity
2.62-2.82
2.86
Transparency
Translucent
Opaque
Density
2.7-4 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Europe
Bulgaria, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Malta, Poland, Portugal, Romania, Slovenia, Spain, Sweden, The Czech Republic
Germany, Hungary, Italy, Portugal, Spain
Deposits in Western Continents
South America
Bolivia, Colombia
-
Deposits in Oceania Continent
Australia
Central Australia, South Australia, Western Australia
New Zealand, Western Australia