Definition
Trachyandesite is an extrusive igneous rock.
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Discoverer
Unknown
Unknown
Etymology
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Foliated, Platy
Color
Black, Brown, Light to Dark Grey
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Durability
Durable
Durable
Appearance
Dull and Soft
Layered and Shiny
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Sculpture
Artifacts
Commercial Uses
Creating Artwork, Pottery
Used in aquariums, Writing Slates
Types
Basaltic Trachyandesite
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Easily splits into thin plates, Smooth to touch
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Figurines
Used
Not Yet Used
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.
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Mineral Content
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
CaO, Carbon Dioxide, MgO
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Streak
Light to dark brown
White
Porosity
Less Porous
Highly Porous
Compressive Strength
Not Available
Specific Gravity
2.8-3
2.5-2.9
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
2.8-2.9 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Impact Resistant, Pressure Resistant, Water Resistant
Deposits in Eastern Continents
Asia
India, Russia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Africa
South Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Europe
Iceland
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Brazil
Brazil, Colombia, Guyana
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, New Zealand, Queensland