Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Origin
Romania and Moldova, Europe
USA
Discoverer
Unknown
Unknown
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 pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
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
Quench
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Brown, Colourless, Green, Grey, Pink, White
Durability
Durable
Durable
Appearance
Vesicular
Dull and Soft
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
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Commemorative Tablets, Creating Artwork
Creating Artwork, Gemstone
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Not Available
Features
Host Rock for Lead, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
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
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. Pseudotachylite 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
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
White
Light to dark brown
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Vitreous
Compressive Strength
Not Available
Cleavage
Perfect
Irregular
Toughness
Not Available
Not Available
Specific Gravity
2.86-2.87
2.46-2.86
Transparency
Translucent
Transparent to Translucent
Density
2.77-2.771 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Not Yet Found
South Korea
Africa
Not Yet Found
Western Africa
Europe
France, Greece, Romania, Scotland, Spain
Great Britain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
USA
Not Yet Found
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Not Yet Found
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, Western Australia
Dacite vs Pseudotachylite 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 Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Dacite and Properties of Pseudotachylite. Learn more about Dacite vs Pseudotachylite in the next section. The interior uses of Dacite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Dacite and Pseudotachylite, 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 Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Dacite and Pseudotachylite
Here you can know more about Dacite and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Dacite and Pseudotachylite 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 Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Igneous Rocks. When we have to compare Dacite vs Pseudotachylite, 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, Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. Appearance of Dacite is Vesicular and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Dacite vs Pseudotachylite. The hardness of Dacite is 2-2.25 and that of Pseudotachylite is 7. The types of Dacite are Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite whereas types of Pseudotachylite are Not Available. 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 Pseudotachylite is light to dark brown. The specific heat capacity of Dacite is 0.92 kJ/Kg K and that of Pseudotachylite 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 Pseudotachylite is heat resistant.