Obsidian

Banded iron formation

Obsidian and Banded iron formation

Obsidian

Banded iron formation

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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

Banded iron formation are distinctive units of sedimentary rock that are almost always of Precambrian age

1.2 History

1.2.1 Origin

Ethiopia

Western Australia, Minnesota

1.2.2 Discoverer

Obsius

Unknown

1.3 Etymology

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

From its formation process

1.4 Class

Igneous Rocks

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness 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

Banded, Trellis

2.2 Color

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

Red, 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

Layered, Banded, Veined and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes

3.1.2 Exterior Uses

Garden Decoration

Paving Stone, Office Buildings

3.1.3 Other Architectural Uses

Not Yet Used

Curbing, Whetstones

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As Dimension Stone, Used for flooring, stair treads, borders and window sills.

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

As a touchstone, Cemetery Markers, Creating Artwork

4 Types

4.1 Types

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

Algoma-type , Lake Superior-type, Superior-type and Taconite

4.2 Features

Blocks negativity, Helps to protect against depression

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

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Not Yet 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.

The banded iron layers are formed in sea water when oxygen is released by photosynthetic cyano-bacteria. The oxygen then combines with dissolved iron in ocean to form insoluble iron oxides, which precipitated out, forming a thin layer of banded iron formation on ocean floor.

5.2 Composition

5.2.1 Mineral Content

Not Available

Hematite, Magnetite, 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

Fe, Iron(III) 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

Chemical 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, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.5

5.5-6

6.1.2 Grain Size

Not Applicable

Large and Coarse Grained

6.1.3 Fracture

Conchoidal

Uneven, Splintery or Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Very Less Porous

Highly Porous

6.1.6 Luster

Vitreous

Earthy

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

Imperfect

6.1.9 Toughness

Not Available

1.5

6.1.10 Specific Gravity

2.6-2.7

5.0-5.3

6.1.11 Transparency

Translucent

Translucent to 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)▶

3.20 kJ/Kg K

Rank: 1 (Overall)▶

▲

What Is Granulite

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▶

1.09 (What Is Trave..)

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6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

China, India, Iran, Iraq, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

7.1.2 Africa

Kenya

Kenya, Morocco, South Africa, Tanzania

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

7.1.4 Others

Not Yet Found

Greenland, Mid-Atlantic Ridge

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Bolivia, Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

New South Wales, Queensland, South Australia, Western Australia

All about Obsidian and Banded iron formation Properties

Know all about Obsidian and Banded iron formation properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Banded iron formation belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Banded iron formation is Banded, Trellis. Obsidian appears Shiny and Banded iron formation appears Layered, Banded, Veined and Shiny. The luster of Obsidian is vitreous while that of Banded iron formation is earthy. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Banded iron formation is available in red, reddish brown colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Banded iron formation are as a touchstone, cemetery markers, creating artwork.