Definition
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
Jaspillite is an iron rich chemically formed rock which is common in banded iron formation rocks
History
Origin
Germany
Western Australia, Minnesota
Discoverer
Van Tooren
Unknown
Etymology
From Greek tephra, ashes from Indo-European base, to burn
From Jaspilite (Mineral), a compact siliceous rock which resembles jasper
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Family
Group
Volcanic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Banded, Trellis
Color
Black, Brown, Green, Grey, White
Red, Reddish Brown
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Vesicular
Banded and Glassy
Architecture
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 Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Landscaping
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
-
Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery, Monuments
Other Uses
Commercial Uses
Production of Lime, Soil Conditioner
Creating Artwork, Jewelry
Types
Igneous rock
Algoma-type , Lake Superior-type and Superior-type
Features
Host Rock for Lead
Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Present
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.
Jaspillite is a type of sedimentary rock which is formed by the compaction and sedimentation of pieces of broken or weathered rocks and minerals.
Composition
Mineral Content
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
Coesite, Quartz, Sand
Compound Content
CaO, Carbon Dioxide, MgO, Silicon Dioxide
Fe, Iron(III) Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion
Physical Properties
Hardness
6.53
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Large and Coarse Grained
Fracture
Uneven
Conchoidal
Streak
Bluish Black
White
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Earthy
Compressive Strength
90.00 N/mm2230.00 N/mm2
0.15
450
👆🏻
Cleavage
Crenulation and Pervasive
-
Toughness
2.4
-
Specific Gravity
2.865.0-5.3
0
8.4
👆🏻
Transparency
Opaque
Translucent to Opaque
Density
2.8-2.9 g/cm30-5.7 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K3.20 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
Russia
Africa
Namibia, Uganda
-
Europe
Germany, Hungary, Italy, Portugal, Spain
Ukraine
Others
-
-
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Brazil
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
Western Australia