Definition
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Discoverer
Abraham Gottlob Werner
Unknown
Etymology
From Old French esclate, from esclat (French éclat)
from French néphéline, from Greek nephelē
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Foliated
Aphanitic
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Phyllite, Schist, and Slate
Peralkaline Nephelinite
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Host Rock for Lead
Archaeological Significance
Formation
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
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
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Fine Grained
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Luster
Dull
Vitreous to Metallic
Specific Gravity
2.65-2.8
2.4-2.9
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
Japan
Africa
-
Rwanda, Tanzania
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
-
Others
Arctic
Hawaii Islands
Deposits in Western Continents
North America
USA
Canada, USA
South America
Brazil
Colombia
Deposits in Oceania Continent
All about Slate and Nephelinite Properties
Know all about Slate and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Slate belongs to Metamorphic Rocks while Nephelinite belongs to Igneous Rocks.Texture of Slate is Foliated whereas that of Nephelinite is Aphanitic. Slate appears Dull and Nephelinite appears Skeletal. The luster of Slate is dull while that of Nephelinite is vitreous to metallic. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Nephelinite is available in black, brown, green, grey, white colors. The commercial uses of Slate are blackboards, commemorative tablets, laboratory bench tops, standard material for the bed of billiard table, standard material for the beds of pool and snooker table, tombstones, used in aquariums, writing slates and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).