Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
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
Romania and Moldova, Europe
USA, Australia
Discoverer
Unknown
Tornebohm
Etymology
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy, Mud-rich, Rough
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, White
Durability
Durable
Durable
Appearance
Vesicular
Dull
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
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 Yet Used
Not Applicable
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Endoskarns
Features
Host Rock for Lead, Is one of the oldest rock
Host Rock for Lead, Zinc and Copper Deposits
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Used
Formation
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
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
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Au, CaO, Carbon Dioxide, Cu, Fe, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
Types of Erosion
Chemical Erosion
Not Applicable
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Irregular
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Waxy and Dull
Toughness
Not Available
2.4
Specific Gravity
2.86-2.87
2.86
Transparency
Translucent
Opaque
Density
2.77-2.771 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
China, India, Russia, Saudi Arabia, South Korea, Sri Lanka
Africa
Not Yet Found
South Africa, Western Africa
Europe
France, Greece, Romania, Scotland, Spain
United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Colombia, Paraguay
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, Western Australia
Dacite 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. Dacite vs Skarn characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Dacite and Properties of Skarn. Learn more about Dacite vs Skarn in the next section. The interior uses of Dacite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Skarn include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Dacite and Skarn, they have various applications in construction industry. The uses of Dacite in construction industry include As dimension stone, Construction aggregate, For road aggregate, Landscaping 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 Dacite and Skarn
Here you can know more about Dacite and Skarn. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Dacite and Skarn consists of mineral content and compound content. The mineral content of Dacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon and mineral content of Skarn includes Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite. You can also check out the list of all Igneous Rocks. When we have to compare Dacite vs Skarn, the texture, color and appearance plays an important role in determining the type of rock. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas, Skarn is available in black, brown, colourless, green, grey, white colors. Appearance of Dacite is Vesicular and that of Skarn is Dull. Properties of rock is another aspect for Dacite vs Skarn. The hardness of Dacite is 2-2.25 and that of Skarn is 6.5. The types of Dacite are Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite 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 Dacite is white while that of Skarn is light to dark brown. The specific heat capacity of Dacite is 0.92 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.Dacite is heat resistant, impact resistant, pressure resistant, wear resistant whereas Skarn is heat resistant.
