1 Definition
1.1 Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
1.2 History
1.2.1 Origin
Romania and Moldova, Europe
USA
1.2.2 Discoverer
1.3 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 17th century, because of its greasy feel and use like a soap
1.4 Class
Igneous Rocks
Metamorphic Rocks
1.4.1 Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Aphanitic to Porphyritic
Polished
2.2 Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Black to Grey, Green, Grey
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
Vesicular
Dull, Banded and Foilated
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Facing Stone, Garden Decoration
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Manufacture of Magnesium and Dolomite Refractories
3.2.2 Medical Industry
Not Yet Used
Taken as a Supplement for Calcium or Magnesium
3.3 Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
3.4 Other Uses
3.4.1 Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
4 Types
4.1 Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Not Available
4.2 Features
Host Rock for Lead, Is one of the oldest rock
Host Rock for Lead
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Not Applicable
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
4.3.3 Sculpture
4.3.4 Famous Sculptures
Not Applicable
Data Not Available
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
5.2 Composition
5.2.1 Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
5.2.2 Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
CaO, Mg, MgO
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Not Applicable
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion
Not Applicable
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Medium to Fine Coarse Grained
Fine Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
6.1.6 Luster
Subvitreous to Dull
Greasy
6.1.7 Compressive Strength
6.1.8 Cleavage
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
2.77-2.771 g/cm32.8-2.9 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K0.88 kJ/Kg K
0.14
3.2
6.2.2 Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Not Yet Found
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
7.1.2 Africa
Not Yet Found
Egypt, Ethiopia, Ghana, South Africa, Western Africa
7.1.3 Europe
France, Greece, Romania, Scotland, Spain
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
7.1.4 Others
Not Yet Found
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
7.2.2 South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Colombia
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, South Australia, Western Australia
Central Australia, New Zealand, Queensland