Definition
Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar
  
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth
  
History
  
  
Origin
France
  
Ethiopia
  
Discoverer
Alexandre Brongniart
  
Obsius
  
Etymology
From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones
  
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
  
Class
Sedimentary Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Medium Hardness Rock
  
Family
  
  
Group
Not Applicable
  
Volcanic
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Opaque Rock
  
Texture
Clastic
  
Glassy
  
Color
Reddish Brown
  
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
No
  
No
  
Acid Resistant
Yes
  
No
  
Appearance
Rough and Dull
  
Shiny
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
  
Decorative Aggregates, Interior Decoration
  
Exterior Uses
Paving Stone, Office Buildings
  
Garden Decoration
  
Other Architectural Uses
Whetstones
  
Not Yet Used
  
Industry
  
  
Construction Industry
Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar
  
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
  
Medical Industry
Not Yet Used
  
Surgery
  
Antiquity Uses
Artifacts, Sculpture, Small Figurines
  
Artifacts, Jewellery
  
Other Uses
  
  
Commercial Uses
In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones
  
Creating Artwork, Mirror, Used in aquariums
  
Types
Not Available
  
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
  
Features
Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock
  
Blocks negativity, Helps to protect against depression
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Not Yet Used
  
Famous Monuments
Not Applicable
  
Not Applicable
  
Sculpture
Used
  
Not Yet Used
  
Famous Sculptures
Data Not Available
  
Not Applicable
  
Pictographs
Not Used
  
Used
  
Petroglyphs
Not Used
  
Used
  
Figurines
Used
  
Not Yet 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.
  
When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.
  
Composition
  
  
Mineral Content
Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz
  
Not Available
  
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
No
  
Yes
  
Types of Metamorphism
Not Applicable
  
Burial Metamorphism, Cataclastic Metamorphism, Contact 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
  
Chemical Erosion, Coastal Erosion, Glacier Erosion
  
Physical Properties
  
  
Hardness
6-7
  
5-5.5
  
Grain Size
Coarse Grained
  
Not Applicable
  
Fracture
Conchoidal
  
Conchoidal
  
Streak
White
  
White
  
Porosity
Highly Porous
  
Very Less Porous
  
Luster
Dull
  
Vitreous
  
Compressive Strength
Not Available
  
Cleavage
Not Available
  
Non-Existent
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
0
  
2.6-2.7
  
Transparency
Opaque
  
Translucent
  
Density
Not Available
  
2.6 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.92 kJ/Kg K
  
10
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
  
Heat Resistant, Impact Resistant
  
Deposits in Eastern Continents
  
  
Asia
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
  
Afghanistan, Indonesia, Japan, Russia
  
Africa
Namibia, Nigeria, South Africa
  
Kenya
  
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
  
Greece, Hungary, Iceland, Italy, Turkey
  
Others
Greenland
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Canada, Mexico, USA
  
South America
Brazil
  
Argentina, Chile, Ecuador, Peru
  
Deposits in Oceania Continent
  
  
Australia
New South Wales, New Zealand
  
New Zealand
  
Arkose vs Obsidian Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Arkose vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Arkose and Properties of Obsidian. Learn more about Arkose vs Obsidian in the next section. The interior uses of Arkose include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Arkose and Obsidian, they have various applications in construction industry. The uses of Arkose in construction industry include Cement manufacture, Construction aggregate, For road aggregate, Production of glass and ceramics, Raw material for the manufacture of mortar and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Arkose and Obsidian
Here you can know more about Arkose and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Arkose and Obsidian consists of mineral content and compound content. The mineral content of Arkose includes Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz and mineral content of Obsidian is not available. You can also check out the list of all Sedimentary Rocks. When we have to compare Arkose vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Arkose is available in reddish brown colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Arkose is Rough and Dull and that of Obsidian is Shiny. Properties of rock is another aspect for Arkose vs Obsidian. The hardness of Arkose is 6-7 and that of Obsidian is 5-5.5. The types of Arkose are Not Available whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Arkose and Obsidian is white. The specific heat capacity of Arkose is Not Available and that of Obsidian is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Arkose is heat resistant, impact resistant, pressure resistant whereas Obsidian is heat resistant, impact resistant.