Arkose

Obsidian

Arkose and Obsidian

Arkose

Obsidian

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1 Definition

1.1 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

1.2 History

1.2.1 Origin

France

Ethiopia

1.2.2 Discoverer

Alexandre Brongniart

Obsius

1.3 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

1.4 Class

Sedimentary Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Clastic

Glassy

2.2 Color

Reddish Brown

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Rough and Dull

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

Paving Stone, Office Buildings

Garden Decoration

3.1.3 Other Architectural Uses

Whetstones

Not Yet Used

3.2 Industry

3.2.1 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

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

In aquifers, Soil Conditioner, Source of Magnesia (MgO), Tombstones

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Not Available

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

4.2 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

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Present

Absent

5 Formation

5.1 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.

5.2 Composition

5.2.1 Mineral Content

Calcite, Clay, Clay Minerals, Feldspar, Micas, Quartz

Not Available

5.2.2 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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Not Applicable

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-75-5.5

1 7

6.1.2 Grain Size

Coarse Grained

Not Applicable

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Highly Porous

Very Less Porous

6.1.6 Luster

Dull

Vitreous

6.1.7 Compressive Strength

NA0.15 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

02.6-2.7

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

Not Available2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

Namibia, Nigeria, South Africa

Kenya

7.1.3 Europe

Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Greenland

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Mexico, USA

7.2.2 South America

Brazil

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand

New Zealand

All about Arkose and Obsidian Properties

Know all about Arkose and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Arkose belongs to Sedimentary Rocks while Obsidian belongs to Igneous Rocks.Texture of Arkose is Clastic whereas that of Obsidian is Glassy. Arkose appears Rough and Dull and Obsidian appears Shiny. The luster of Arkose is dull while that of Obsidian is vitreous. Arkose is available in reddish brown colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Arkose are in aquifers, soil conditioner, source of magnesia (mgo), tombstones and that of Obsidian are creating artwork, mirror, used in aquariums.