Definition
Trachyandesite is an extrusive igneous rock.
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
Discoverer
Unknown
Unknown
Etymology
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
From 17th century, because of its greasy feel and use like a soap
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Polished
Color
Black, Brown, Light to Dark Grey
Black, Black to Grey, Green, Grey
Durability
Durable
Durable
Appearance
Dull and Soft
Dull, Banded and Foilated
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Sculpture
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Creating Artwork, Pottery
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
Types
Basaltic Trachyandesite
Not Available
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
Famous Sculptures
Data Not Available
Data Not Available
Formation
Trachyandesite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
CaO, Mg, MgO
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional 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, Coastal Erosion, Water Erosion, Wind Erosion
Not Applicable
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
Light to dark brown
Black
Porosity
Less Porous
Less Porous
Specific Gravity
2.8-3
2.86
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Africa
South Africa
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Europe
Iceland
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Colombia
Deposits in Oceania Continent
Australia
Not Yet Found
Central Australia, New Zealand, Queensland
All about Trachyandesite and Soapstone Properties
Know all about Trachyandesite and Soapstone properties here. All properties of rocks are important as they define the type of rock and its application. Trachyandesite belongs to Igneous Rocks while Soapstone belongs to Metamorphic Rocks.Texture of Trachyandesite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Soapstone is Polished. Trachyandesite appears Dull and Soft and Soapstone appears Dull, Banded and Foilated. The luster of Trachyandesite is earthy while that of Soapstone is greasy. Trachyandesite is available in black, brown, light to dark grey colors whereas Soapstone is available in black, black to grey, green, grey colors. The commercial uses of Trachyandesite are creating artwork, pottery 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).