Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Talc carbonate is nothing but a rock sequence or a mineral composition found in metamorphic ultramafic rocks.
Origin
Germany
China, USA, Middle east
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From medieval Latin, talcum
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Very Soft
Color
Black, Brown, Green, Grey, White
Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Vesicular
Soft
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Garden Decoration
Other Architectural Uses
Curbing
Powder
Construction Industry
Landscaping
Source of calcium
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery, Monuments, Sculpture, Small Figurines
Commercial Uses
Production of Lime, Soil Conditioner
Manufacturing of baby powder
Types
Igneous rock
Sedimentary rock
Features
Host Rock for Lead
Easily splits into thin plates, Generally rough to touch, Host Rock for Lead
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Talc Carbonate 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
Carbonate, Chlorite, Magnesium
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
CaO, Carbon Dioxide, MgO
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
-
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Streak
Bluish Black
White
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Pearly
Cleavage
Crenulation and Pervasive
Perfect
Specific Gravity
2.86
2.86
Transparency
Opaque
Translucent
Density
2.8-2.9 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
Namibia, Uganda
Ethiopia, Ghana, Western Africa
Europe
Germany, Hungary, Italy, Portugal, Spain
England
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Argentina, Bolivia, Uruguay
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Central Australia, South Australia, Western Australia