Gossan and Gneiss
Definition
Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
History
Origin
Indonesia
Unknown
Discoverer
Cornish Gossen
Unknown
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Texture
Rough, Sandy
Banded, Foliated, Platy
Color
Brown, Brown- Black, Gold, Green, Rust
Black, Brown, Pink, Red, White
Maintenance
Less
More
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
Yes
Yes
Wind Resistant
No
Yes
Acid Resistant
No
No
Appearance
Dull and Banded
Foliated
Uses
Architecture
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts
Other Uses
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Types
Translocated gossan and Leakage gossan
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Clasts are smooth to touch, Easily splits into thin plates
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Konark Sun Temple in India, Washington Monument, US
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Not Yet Used
Fossils
Absent
Absent
Formation
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Composition
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
No
Yes
Types of Metamorphism
Not Applicable
Impact Metamorphism
Weathering
No
Yes
Types of Weathering
Not Applicable
Biological Weathering, Mechanical Weathering
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Properties
Physical Properties
Hardness
4-5
7
Grain Size
Fine to Medium Grained
Medium to Coarse Grained
Fracture
Conchoidal
Irregular
Streak
White to Grey
White
Porosity
Highly Porous
Very Less Porous
Luster
Metallic
Dull
Compressive Strength
Not Available
125.00 N/mm2
17
Cleavage
Not Available
Poor
Toughness
Not Available
1.2
Specific Gravity
2.0
2.5-2.7
Transparency
Opaque
Translucent to Opaque
Density
Not Available
2.6-2.9 g/cm3
Thermal Properties
Specific Heat Capacity
0.24 kJ/Kg K
24
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Reserves
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
Albania, France, Germany, Great Britain, United Kingdom
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Brazil, Colombia, Ecuador
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria
All about Gossan and Gneiss Properties
Know all about Gossan and Gneiss properties here. All properties of rocks are important as they define the type of rock and its application. Gossan and Gneiss belong to Metamorphic Rocks.Texture of Gossan is Rough, Sandy whereas that of Gneiss is Banded, Foliated, Platy. Gossan appears Dull and Banded and Gneiss appears Foliated. The luster of Gossan is metallic while that of Gneiss is dull. Gossan is available in brown, brown- black, gold, green, rust colors whereas Gneiss is available in black, brown, pink, red, white colors. The commercial uses of Gossan are cemetery markers, commemorative tablets, gemstone and that of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums.
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