Definition
Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Discoverer
Unknown
Unknown
Etymology
From French schiste, Greek skhistos i.e. split
from French néphéline, from Greek nephelē
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated, Platy
Aphanitic
Color
Black, Blue, Brown, Dark Brown, Green, Grey, Silver
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Appearance
Layered and Shiny
Skeletal
Interior Uses
Decorative Aggregates, Floor Tiles, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, for Road Aggregate, Roadstone
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Used in aquariums, Writing Slates
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.
Peralkaline Nephelinite
Features
Easily splits into thin plates, Smooth to touch
Host Rock for Lead
Archaeological Significance
Formation
Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.
Nephelinite 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.
Mineral Content
Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc
Clinopyroxene, Nepheline, Plagioclase
Compound Content
CaO, Carbon Dioxide, MgO
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
-
Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Porosity
Highly Porous
Less Porous
Luster
Shiny
Vitreous to Metallic
Specific Gravity
2.5-2.9
2.4-2.9
Transparency
Opaque
Opaque
Density
2.8-2.9 g/cm3
2.5-3 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Water Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam
Japan
Africa
Egypt, Ethiopia, Morocco, Nigeria, South Africa
Rwanda, Tanzania
Europe
Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland
-
Deposits in Western Continents
North America
Canada, Costa Rica, Cuba, Mexico, Panama, USA
Canada, USA
South America
Brazil, Colombia, Guyana
Colombia
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland
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All about Schist and Nephelinite Properties
Know all about Schist and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Schist belongs to Metamorphic Rocks while Nephelinite belongs to Igneous Rocks.Texture of Schist is Foliated, Platy whereas that of Nephelinite is Aphanitic. Schist appears Layered and Shiny and Nephelinite appears Skeletal. The luster of Schist is shiny while that of Nephelinite is vitreous to metallic. Schist is available in black, blue, brown, dark brown, green, grey, silver colors whereas Nephelinite is available in black, brown, green, grey, white colors. The commercial uses of Schist are used in aquariums, writing slates and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).