Definition
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
  
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
  
History
  
  
Origin
France
  
England
  
Discoverer
Alexandre Brongniart
  
Unknown
  
Etymology
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
  
From Old French esclate, from esclat (French éclat)
  
Class
Sedimentary Rocks
  
Metamorphic Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Not Applicable
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Clastic
  
Foliated
  
Color
Reddish Brown
  
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
Yes
  
Wind Resistant
No
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Rough and Dull
  
Dull
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
  
Exterior Uses
Paving Stone, Office Buildings
  
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
  
Other Architectural Uses
Whetstones
  
Curbing
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
  
As Dimension Stone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Sculpture, Small Figurines
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones
  
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
  
Types
Not Available
  
Not Available
  
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
  
Easily splits into thin plates, Surfaces are often shiny, Very fine grained rock
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Used
  
Used
  
Famous Sculptures
Data Not Available
  
Data Not Available
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Used
  
Fossils
Present
  
Absent
  
Formation
Arkose rock forms from the weathering of feldspar-rich igneous or metamorphic rock, most commonly granitic rocks, which are primarily composed of quartz and feldspar.
  
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
  
Composition
  
  
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
  
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Weathering
Yes
  
Yes
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
Yes
  
Yes
  
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
6-7
  
3-4
  
Grain Size
Coarse Grained
  
Very fine-grained
  
Fracture
Conchoidal
  
Splintery
  
Streak
White
  
Light to dark brown
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Dull
  
Dull
  
Compressive Strength
Not Available
  
30.00 N/mm
2
  
30
Cleavage
Not Available
  
Slaty
  
Toughness
Not Available
  
1.2
  
Specific Gravity
0
  
2.65-2.8
  
Transparency
Opaque
  
Opaque
  
Density
Not Available
  
2.6-2.8 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.76 kJ/Kg K
  
17
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
China, India, Turkey
  
Africa
Namibia, Nigeria, South Africa
  
Not Yet Found
  
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
  
Others
Greenland
  
Arctic
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
USA
  
South America
Brazil
  
Brazil
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand
  
Not Yet Found