Obsidian

Arkose

Obsidian and Arkose

Obsidian

Arkose

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1 Definition

1.1 Definition

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

Arkose is a sedimentary rock, specifically a type of sandstone containing at least 25% feldspar

1.2 History

1.2.1 Origin

Ethiopia

France

1.2.2 Discoverer

Obsius

Alexandre Brongniart

1.3 Etymology

From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

From Auvergne region of France used by a French geologist Alexandre Brongniart in 1826 who applied this term to some feldspathic sandstones

1.4 Class

Igneous Rocks

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Opaque Rock

Coarse Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy

Clastic

2.2 Color

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

Reddish Brown

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

59% Sedimentary Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

62% Sedimentary Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

43% Sedimentary Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

38% Sedimentary Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

22% Sedimentary Rocks Rocks have it !

2.5 Appearance

Shiny

Rough and Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration

Paving Stone, Office Buildings

3.1.3 Other Architectural Uses

Not Yet Used

Whetstones

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Cement Manufacture, Construction Aggregate, for Road Aggregate, Production of Glass and Ceramics, Raw material for the manufacture of mortar

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

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

4 Types

4.1 Types

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

Not Available

4.2 Features

Blocks negativity, Helps to protect against depression

Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

Present

5 Formation

5.1 Formation

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.

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.

5.2 Composition

5.2.1 Mineral Content

Not Available

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

5.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

19% Sedimentary Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

78% Sedimentary Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

86% Sedimentary Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.5

6-7

6.1.2 Grain Size

Not Applicable

Coarse Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Very Less Porous

Highly Porous

6.1.6 Luster

Vitreous

Dull

6.1.7 Compressive Strength

What Is Flint

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▶

▼

0.15 N/mm²

Rank: 33 (Overall)▶

Not Available

Rank: N/A (Overall)▶

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What Is Obsidian

⊕

▶

175 (What Is Grani..)

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6.1.8 Cleavage

Non-Existent

Not Available

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.7

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³

Not Available

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

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▶

▼

0.92 kJ/Kg K

Rank: 10 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

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6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

China, India, Kazakhstan, Mongolia, Russia, Uzbekistan

7.1.2 Africa

Kenya

Namibia, Nigeria, South Africa

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

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

7.1.4 Others

Not Yet Found

Greenland

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

New South Wales, New Zealand

All about Obsidian and Arkose Properties

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