Obsidian

Anthracite

Obsidian vs 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

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

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

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Contact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.51-1.5

1 7

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

0.15 N/mm²NA

0.15 450

6.1.8 Cleavage

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.71.1-1.4

0 8.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³1.25-2.5 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K1.32 kJ/Kg K

0.14 3.2

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

Obsidian vs Anthracite Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Obsidian and Anthracite Reserves. 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. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Obsidian vs Anthracite information and Obsidian vs Anthracite characteristics in the upcoming sections.

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Obsidian vs Anthracite 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. Obsidian vs Anthracite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Anthracite. Learn more about Obsidian vs Anthracite in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Anthracite include Not yet used. Due to some exceptional properties of Obsidian and Anthracite, they have various applications in construction industry. The uses of Obsidian in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Anthracite include Cement manufacture, For road aggregate, Making natural cement, Steel production.

More about Obsidian and Anthracite

Here you can know more about Obsidian and Anthracite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Anthracite consists of mineral content and compound content. The mineral content of Obsidian is not available and mineral content of Anthracite includes Calcite, Clay, Clay Minerals. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Anthracite, the texture, color and appearance plays an important role in determining the type of rock. 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. Appearance of Obsidian is Shiny and that of Anthracite is Veined or Pebbled. Properties of rock is another aspect for Obsidian vs Anthracite. The hardness of Obsidian is 5-5.5 and that of Anthracite is 1-1.5. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Anthracite are Semi-anthracite and Meta-anthracite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian is white while that of Anthracite is black. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Anthracite is 1.32 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Obsidian is heat resistant, impact resistant whereas Anthracite is heat resistant, water resistant.