Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Discoverer
Cornish Gossen
Unknown
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
from French néphéline, from Greek nephelē
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Rough, Sandy
Aphanitic
Color
Brown, Brown- Black, Gold, Green, Rust
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Banded
Skeletal
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, 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, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Translocated gossan and Leakage gossan
Peralkaline Nephelinite
Features
Clasts are smooth to touch, Easily splits into thin plates
Host Rock for Lead
Archaeological Significance
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Nephelinite 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
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
-
Contact Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Fine to Medium Grained
Fine Grained
Streak
White to Grey
White
Porosity
Highly Porous
Less Porous
Luster
Metallic
Vitreous to Metallic
Specific Gravity
2.0
2.4-2.9
Transparency
Opaque
Opaque
Density
-9999 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
Japan
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Rwanda, Tanzania
Europe
Albania, France, Germany, Great Britain, United Kingdom
-
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Colombia, Ecuador
Colombia
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
-
Gossan vs Nephelinite 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 Nephelinite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gossan and Properties of Nephelinite. Learn more about Gossan vs Nephelinite in the next section. The interior uses of Gossan include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Gossan and Nephelinite, 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 Nephelinite include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate.
More about Gossan and Nephelinite
Here you can know more about Gossan and Nephelinite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gossan and Nephelinite 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 Nephelinite includes Clinopyroxene, Nepheline, Plagioclase. You can also check out the list of all Metamorphic Rocks. When we have to compare Gossan vs Nephelinite, 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, Nephelinite is available in black, brown, green, grey, white colors. Appearance of Gossan is Dull and Banded and that of Nephelinite is Skeletal. Properties of rock is another aspect for Gossan vs Nephelinite. The hardness of Gossan is 4-5 and that of Nephelinite is 6.5. The types of Gossan are Translocated gossan and Leakage gossan whereas types of Nephelinite are Peralkaline Nephelinite. 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 Nephelinite is white. The specific heat capacity of Gossan is 0.24 kJ/Kg K and that of Nephelinite is 0.88 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 Nephelinite is heat resistant.