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
Icelandite belongs to volcanic igneous rocks which is rich in iron and belongs to andesite rock
Discoverer
Abraham Gottlob Werner
Ian S. E. Carmichael
Etymology
From Old French esclate, from esclat (French éclat)
From its origin place near Cenozoic volcano near the parsonage Þingmúli in East Iceland
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 to Porphyritic
Color
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Bluish - Grey, Grey, Pink, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull
Dull and Soft
Interior Uses
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Office Buildings, Roof Tiles
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone
Cobblestones, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, 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
Cemetery Markers, Creating Artwork
Types
Phyllite, Schist, and Slate
Intermediate volcanic rock
Features
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
Generally rough to touch, High silica content, Is one of the oldest rock
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.
Icelandite 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
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Very fine-grained
Fracture
Splintery
Uneven
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Specific Gravity
2.65-2.8
2.5-2.8
Transparency
Opaque
Opaque
Density
2.6-2.8 g/cm3
2.11-2.36 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Turkey
India, Indonesia, Japan, Nepal, South Korea
Africa
-
Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania
Europe
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom
Deposits in Western Continents
North America
USA
Mexico, USA
South America
Brazil
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
-
New South Wales, New Zealand, Western Australia
All about Slate and Icelandite Properties
Know all about Slate and Icelandite properties here. All properties of rocks are important as they define the type of rock and its application. Slate belongs to Metamorphic Rocks while Icelandite belongs to Igneous Rocks.Texture of Slate is Foliated whereas that of Icelandite is Aphanitic to Porphyritic. Slate appears Dull and Icelandite appears Dull and Soft. The luster of Slate is dull while that of Icelandite is vitreous. Slate is available in black, brown, buff, green, light to dark grey, purple, red, shades of blue colors whereas Icelandite is available in bluish - grey, grey, pink, yellow 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 Icelandite are cemetery markers, creating artwork.