Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Tonalite is a coarse-grained plutonic rock consisting mainly of sodic plagioclase, quartz, and hornblende or other mafic minerals with phaneritic texture
History
Origin
Germany
Tonale, Italy
Discoverer
Van Tooren
Warren Hamilton
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Tonale Pass, northern Italy, + -ite1
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Plutonic
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
Phaneritic
Color
Black, Brown, Green, Grey, White
Black, Brown, Light to Dark Grey, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Banded and Foilated
Architecture
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Landscaping
As Dimension Stone, Cement Manufacture, Cobblestones, Construction Aggregate, for Road Aggregate
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture
Artifacts, Sculpture
Other Uses
Commercial Uses
Production of Lime, Soil Conditioner
Cemetery Markers, Creating Artwork
Types
Igneous rock
Dacite
Features
Host Rock for Lead
Is one of the oldest rock, Typically speckled black and white.
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes tonalite with quartz as major mineral.
Composition
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
NaCl, CaO, MgO, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Wind Erosion
Physical Properties
Hardness
6.56-7
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
Bluish Black
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Compressive Strength
90.00 N/mm2185.00 N/mm2
0.15
450
👆🏻
Cleavage
Crenulation and Pervasive
-
Toughness
2.4
2.1
Specific Gravity
2.862.86-3
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm32.73 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K0.92 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
-
-
Africa
Namibia, Uganda
Egypt
Europe
Germany, Hungary, Italy, Portugal, Spain
Finland, Germany, Italy, Romania, Sweden, Turkey
Others
-
-
Deposits in Western Continents
North America
USA
USA
South America
-
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand, South Australia, Western Australia