Basalt

Obsidian

Basalt and Obsidian

Basalt

Obsidian

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1 Definition

1.1 Definition

Basalt is a common extrusive igneous rock formed by the rapid cooling of basaltic lava exposed at or very near the surface of Earth

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

Egypt

Ethiopia

1.2.2 Discoverer

Georgius Agricola

Obsius

1.3 Etymology

From Late Latin Basaltes (variant of basanites ), very hard stone, which was imported from Ancient Greek Basanites

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

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Glassy

2.2 Color

Black, Brown, Light to Dark Grey

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

Dull and Soft

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Floor Tiles, Homes, Hotels, Kitchens

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, Paving Stone, Garden Decoration, Office Buildings

Garden Decoration

3.1.3 Other Architectural Uses

Curbing, Whetstones

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

Arrowheads, As Dimension Stone, Cobblestones, Cutting Tool, Rail Track Ballast, Roadstone

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts, Monuments

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork, Used in aquariums

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite

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

4.2 Features

Has High structural resistance against erosion and climate, Very fine grained rock

Blocks negativity, Helps to protect against depression

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Easter Island in the Polynesian Triangle, Pacific Ocean, Gateway of India in Mumbai, India, Gol Gumbaz in Karnataka, India

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Basalt forms when lava reaches the Earth's surface near an active volcano. The temperature of lava is between 1100 to 1250° C when it gets to the surface.

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

Olivine, Plagioclase, Pyroxene

Not Available

5.2.2 Compound Content

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

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Not Available

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

65-5.5

1 7

6.1.2 Grain Size

Fine Grained

Not Applicable

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White to Grey

White

6.1.5 Porosity

Less Porous

Very Less Porous

6.1.6 Luster

Not Available

Vitreous

6.1.7 Compressive Strength

37.40 N/mm²0.15 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Non-Existent

6.1.9 Toughness

2.3

Not Available

6.1.10 Specific Gravity

2.8-32.6-2.7

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.9-3.1 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.84 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Russia

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

South Africa

Kenya

7.1.3 Europe

Iceland

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

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

Not Yet Found

New Zealand

All about Basalt and Obsidian Properties

Know all about Basalt and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Basalt and Obsidian belong to Igneous Rocks.Texture of Basalt is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Obsidian is Glassy. Basalt appears Dull and Soft and Obsidian appears Shiny. The luster of Basalt is not available while that of Obsidian is vitreous. Basalt is available in black, brown, light to dark grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Basalt are an oil and gas reservoir, commemorative tablets, creating artwork, used in aquariums and that of Obsidian are creating artwork, mirror, used in aquariums.