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
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 17th century, because of its greasy feel and use like a soap
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Polished
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Black to Grey, Green, Grey
Durability
Durable
Durable
Appearance
Vesicular
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Manufacture of Magnesium and Dolomite Refractories
Medical Industry
-
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
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)
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Metamorphic rock
Features
Host Rock for Lead, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Famous Monuments
-
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
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.
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
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
CaO, Mg, 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
-
Types of Erosion
Chemical Erosion
-
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Greasy
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, Pressure Resistant
Deposits in Eastern Continents
Asia
-
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Africa
-
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Europe
France, Greece, Romania, Scotland, Spain
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, New Zealand, Queensland
All about Dacite and Soapstone Properties
Know all about Dacite and Soapstone properties here. All properties of rocks are important as they define the type of rock and its application. Dacite belongs to Igneous Rocks while Soapstone belongs to Metamorphic Rocks.Texture of Dacite is Aphanitic to Porphyritic whereas that of Soapstone is Polished. Dacite appears Vesicular and Soapstone appears Dull, Banded and Foilated. The luster of Dacite is subvitreous to dull while that of Soapstone is greasy. Dacite is available in bluish - grey, brown, grey, light to dark grey colors whereas Soapstone is available in black, black to grey, green, grey colors. The commercial uses of Dacite are commemorative tablets, creating artwork and that of Soapstone are cemetery markers, creating artwork, gemstone, jewelry, manufacture of soap, solvents, dyes, plastics and fibres, production of lime, source of magnesia (mgo).