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
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
Group
Not Applicable
Volcanic
Other Categories
Coarse Grained Rock, Opaque Rock
Opaque Rock
Color
Reddish Brown
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Rough and Dull
Shiny
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
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
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
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.
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
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic 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, Coastal Erosion, Glacier Erosion
Grain Size
Coarse Grained
Not Applicable
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Very Less Porous
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
Specific Heat Capacity
Not Available
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.
