Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
  
Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock
  
History
  
  
Origin
Indonesia
  
Germany
  
Discoverer
Cornish Gossen
  
Van Tooren
  
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
  
From Greek tephra, ashes from Indo-European base, to burn
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Medium Hardness Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
  
Texture
Rough, Sandy
  
Aphanitic to Porphyritic
  
Color
Brown, Brown- Black, Gold, Green, Rust
  
Black, Brown, Colourless, Green, Grey, White
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
Yes
  
Acid Resistant
No
  
No
  
Appearance
Dull and Banded
  
Vesicular
  
Architecture
  
  
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
  
Decorative Aggregates, Flooring, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Landscaping
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Sculpture
  
Other Uses
  
  
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
  
Production of Lime, Soil Conditioner
  
Types
Translocated gossan and Leakage gossan
  
Not Available
  
Features
Clasts are smooth to touch, Easily splits into thin plates
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Used
  
Not Used
  
Petroglyphs
Used
  
Not Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
  
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.
  
Composition
  
  
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
  
Alkali feldspar, Nepheline, Plagioclase, Pyroxene
  
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
  
CaO, Carbon Dioxide, MgO, Silicon Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
  
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion
  
Physical Properties
  
  
Hardness
4-5
  
6.5
  
Grain Size
Fine to Medium Grained
  
Medium to Fine Coarse Grained
  
Fracture
Conchoidal
  
Uneven
  
Streak
White to Grey
  
Bluish Black
  
Porosity
Highly Porous
  
Very Less Porous
  
Luster
Metallic
  
Subvitreous to Dull
  
Compressive Strength
Not Available
  
90.00 N/mm
2
  
22
Cleavage
Not Available
  
Crenulation and Pervasive
  
Toughness
Not Available
  
2.4
  
Specific Gravity
2.0
  
2.86
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.8-2.9 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.24 kJ/Kg K
  
24
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Indonesia, Russia, Singapore, South Korea
  
Not Yet Found
  
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
  
Namibia, Uganda
  
Europe
Albania, France, Germany, Great Britain, United Kingdom
  
Germany, Hungary, Italy, Portugal, Spain
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Brazil, Colombia, Ecuador
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, South Australia, Western Australia
  
New Zealand, Western Australia
  
Gossan vs Tephrite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Gossan vs Tephrite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gossan and Properties of Tephrite. Learn more about Gossan vs Tephrite in the next section. The interior uses of Gossan include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Tephrite include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Gossan and Tephrite, they have various applications in construction industry. The uses of Gossan in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate and that of Tephrite include Landscaping.
More about Gossan and Tephrite
Here you can know more about Gossan and Tephrite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gossan and Tephrite consists of mineral content and compound content. The mineral content of Gossan includes Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon and mineral content of Tephrite includes Alkali feldspar, Nepheline, Plagioclase, Pyroxene. You can also check out the list of all Metamorphic Rocks. When we have to compare Gossan vs Tephrite, the texture, color and appearance plays an important role in determining the type of rock. Gossan is available in brown, brown- black, gold, green, rust colors whereas, Tephrite is available in black, brown, colourless, green, grey, white colors. Appearance of Gossan is Dull and Banded and that of Tephrite is Vesicular. Properties of rock is another aspect for Gossan vs Tephrite. The hardness of Gossan is 4-5 and that of Tephrite is 6.5. The types of Gossan are Translocated gossan and Leakage gossan whereas types of Tephrite are Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Gossan is white to grey while that of Tephrite is bluish black. The specific heat capacity of Gossan is 0.24 kJ/Kg K and that of Tephrite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Gossan is heat resistant, impact resistant, pressure resistant whereas Tephrite is heat resistant, impact resistant.