Definition
Definition
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
History
Origin
France
Unknown
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 German Grauwacke, from grau grey + wacke
Class
Sedimentary Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Not Applicable
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Texture
Clastic
Clastic
Color
Reddish Brown
Beige, Black, Brown, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Rough and Dull
Dull
Uses
Architecture
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Exterior Uses
Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Whetstones
Curbing, Whetstones
Industry
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Medical Industry
Not Available
Not Available
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Other Uses
Commercial Uses
In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Types
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Used
Used
Famous Sculptures
Not Available
Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not Used
Figurines
Used
Used
Fossils
Present
Present
Formation
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.
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
Composition
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Not Applicable
Not Applicable
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Properties
Physical Properties
Hardness
6-76-7
1
7
👆🏻
Grain Size
Coarse Grained
Angular and Fine
Fracture
Conchoidal
Conchoidal
Streak
White
White
Porosity
Highly Porous
Highly Porous
Luster
Dull
Dull
Compressive Strength
NANA
0.15
450
👆🏻
Cleavage
Not Available
Perfect
Toughness
Not Available
2.6
Specific Gravity
02.2-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
Not Available2.6-2.61 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
NANA
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Reserves
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Namibia, Nigeria, South Africa
Namibia, Nigeria, South Africa
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Greenland
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
New South Wales, New Zealand