Definition
Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Origin
USA, Australia
Italy
Discoverer
Tornebohm
Unknown
Etymology
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
From a Latin word tophous then in Italian tufo and finally tuff
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Mud-rich, Rough
Clastic, Pyroclastic
Color
Black, Brown, Green, Grey, White
Brown, Grey, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
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
Building houses or walls, Construction Aggregate
Medical Industry
Not Applicable
Not Available
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Creating Artwork
Types
Endoskarns
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Features
Host Rock for Lead, Zinc and Copper Deposits
Always found as volcanic pipes over deep continental crust
Archaeological Significance
Famous Monuments
Not Available
Easter Island in the Polynesian Triangle, Pacific Ocean
Famous Sculptures
Not Available
Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Formation
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.
Tuff is formed when large masses of ash and sand which are mixed with hot gases are ejected by a volcano and avalanche rapidly down its slopes.
Mineral Content
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Calcite, Chlorite
Compound Content
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Hydrogen Sulfide, Sulfur Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Irregular
Uneven
Streak
Light to dark brown
White
Porosity
Less Porous
Highly Porous
Luster
Waxy and Dull
Vitreous to Dull
Compressive Strength
Not Available
Cleavage
Slaty
Not Available
Toughness
2.4
Not Available
Specific Gravity
2.86
2.73
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
1-1.8 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
Africa
South Africa, Western Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Europe
United Kingdom
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
Not Available
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
Canada
Canada, Costa Rica, Panama, USA
South America
Brazil, Colombia, Paraguay
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Central Australia, Western Australia
Skarn vs Tuff 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. Skarn vs Tuff characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Skarn and Properties of Tuff. Learn more about Skarn vs Tuff in the next section. The interior uses of Skarn include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Tuff include Decorative aggregates, Entryways, Flooring, Homes and Interior decoration. Due to some exceptional properties of Skarn and Tuff, they have various applications in construction industry. The uses of Skarn in construction industry 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 and that of Tuff include Building houses or walls, Construction aggregate.
More about Skarn and Tuff
Here you can know more about Skarn and Tuff. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Skarn and Tuff consists of mineral content and compound content. The mineral content of Skarn includes Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite and mineral content of Tuff includes Calcite, Chlorite. You can also check out the list of all Metamorphic Rocks. When we have to compare Skarn vs Tuff, the texture, color and appearance plays an important role in determining the type of rock. Skarn is available in black, brown, green, grey, white colors whereas, Tuff is available in brown, grey, yellow colors. Appearance of Skarn is Dull and that of Tuff is Dull, Vesicular and Foilated. Properties of rock is another aspect for Skarn vs Tuff. The hardness of Skarn is 6.5 and that of Tuff is 4-6. The types of Skarn are Endoskarns whereas types of Tuff are Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Skarn is light to dark brown while that of Tuff is white. The specific heat capacity of Skarn is 0.92 kJ/Kg K and that of Tuff is 0.20 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Skarn is heat resistant whereas Tuff is heat resistant, impact resistant, pressure resistant, wear resistant.
