Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
Origin
Indonesia
USA, Australia
Discoverer
Cornish Gossen
Tornebohm
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Metamorphic Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Rough, Sandy
Earthy, Mud-rich, Rough
Color
Brown, Brown- Black, Gold, Green, Rust
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Banded
Dull
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, 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
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
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, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Available
Not Applicable
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Translocated gossan and Leakage gossan
Endoskarns
Features
Clasts are smooth to touch, Easily splits into thin plates
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Used
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Not Applicable
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Not Applicable
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Irregular
Streak
White to Grey
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Metallic
Waxy and Dull
Cleavage
Not Available
Slaty
Toughness
Not Available
2.4
Specific Gravity
2.0
2.86
Transparency
Opaque
Opaque
Density
Not Available
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
South Africa, Western Africa
Europe
Albania, France, Germany, Great Britain, United Kingdom
United Kingdom
Others
Not Available
Not Available
Deposits in Western Continents
North America
Canada, USA
Canada
South America
Brazil, Colombia, Ecuador
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
Central Australia, Western Australia
Gossan vs Skarn 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 Skarn characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Gossan and Properties of Skarn. Learn more about Gossan vs Skarn in the next section. The interior uses of Gossan include Countertops, Decorative aggregates and Interior decoration whereas the interior uses of Skarn include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Gossan and Skarn, 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 Skarn include 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, Gold and silver production, Manufacture of magnesium and dolomite refractories.
More about Gossan and Skarn
Here you can know more about Gossan and Skarn. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Gossan and Skarn 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 Skarn includes Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite. You can also check out the list of all Metamorphic Rocks. When we have to compare Gossan vs Skarn, 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, Skarn is available in black, brown, green, grey, white colors. Appearance of Gossan is Dull and Banded and that of Skarn is Dull. Properties of rock is another aspect for Gossan vs Skarn. The hardness of Gossan is 4-5 and that of Skarn is 6.5. The types of Gossan are Translocated gossan and Leakage gossan whereas types of Skarn are Endoskarns. 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 Skarn is light to dark brown. The specific heat capacity of Gossan is 0.24 kJ/Kg K and that of Skarn 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 Skarn is heat resistant.
