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
Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava
Origin
USA, Australia
North America
Discoverer
Tornebohm
Theodor von Gümbel
Etymology
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
From Andes mountains, where it is found in abundance
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Earthy, Mud-rich, Rough
Aphanitic to Porphyritic
Color
Black, Brown, Green, Grey, White
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull and Soft
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Office Buildings, Roof Tiles
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
Cobblestones, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Commemorative Tablets, Creating Artwork
Types
Endoskarns
Icelandite
Features
Host Rock for Lead, Zinc and Copper Deposits
Generally rough to touch, High silica content, Is one of the oldest rock
Archaeological Significance
Famous Monuments
-
Middle of the Earth in Ecuador
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.
Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.
Mineral Content
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon
Compound Content
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Silicon 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
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
-
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Irregular
Uneven
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Luster
Waxy and Dull
Vitreous
Specific Gravity
2.86
2.5-2.8
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.11-2.36 g/cm3
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
India, Indonesia, Japan, Nepal, South Korea
Africa
South Africa, Western Africa
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Europe
United Kingdom
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Deposits in Western Continents
North America
Canada
Mexico, USA
South America
Brazil, Colombia, Paraguay
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Western Australia