Obsidian

Anthracite

Obsidian and Anthracite

Obsidian

Anthracite

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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

Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster

1.2 History

1.2.1 Origin

Ethiopia

Pennsylvania, U.S.

1.2.2 Discoverer

Obsius

Unknown

1.3 Etymology

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

From Greek anthrakites, from anthrax, anthrak meaning coal

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy

Amorphous, Glassy

2.2 Color

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

Black, Brown, Dark Brown, Grey, Light to Dark Grey

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

81% Metamorphic Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

42% Metamorphic Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

19% Metamorphic Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

15% Metamorphic Rocks Rocks have it !

2.5 Appearance

Shiny

Veined or Pebbled

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Not Yet Used

3.1.2 Exterior Uses

Garden Decoration

Not Yet Used

3.1.3 Other Architectural Uses

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production

3.2.2 Medical Industry

Surgery

In Chemical and Pharmaceutical Industry, Manufacture of Aspirins

3.3 Antiquity Uses

Artifacts, Jewellery

Not Yet Used

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry

4 Types

4.1 Types

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

Semi-anthracite and Meta-anthracite

4.2 Features

Blocks negativity, Helps to protect against depression

Helps in production of Heat and Electricity, Used as fossil fuel

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

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

4.4 Fossils

Absent

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.

Anthracite forms from the accumulation of plant debris in a swamp environment. When plant debris dies and falls into the swamp, the standing water of the swamp protects it from decay.

5.2 Composition

5.2.1 Mineral Content

Not Available

Calcite, Clay, Clay Minerals

5.2.2 Compound Content

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

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

50% Metamorphic Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Contact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

77% Metamorphic Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.5

1-1.5

6.1.2 Grain Size

Not Applicable

Medium to Fine Coarse Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

Black

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Vitreous

Shiny

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..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.7

1.1-1.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³

1.25-2.5 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.92 kJ/Kg K

Rank: 10 (Overall)▶

1.32 kJ/Kg K

Rank: 4 (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Water Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam

7.1.2 Africa

Kenya

Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Brazil, Chile, Colombia, Venezuela

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

New South Wales, Queensland, Victoria

All about Obsidian and Anthracite Properties

Know all about Obsidian and Anthracite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Anthracite belongs to Metamorphic Rocks.Texture of Obsidian is Glassy whereas that of Anthracite is Amorphous, Glassy. Obsidian appears Shiny and Anthracite appears Veined or Pebbled. The luster of Obsidian is vitreous while that of Anthracite is shiny. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Anthracite is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Anthracite are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry.