Obsidian

Basalt

Obsidian and Basalt

Obsidian

Basalt

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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

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

1.2 History

1.2.1 Origin

Ethiopia

Egypt

1.2.2 Discoverer

Obsius

Georgius Agricola

1.3 Etymology

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

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

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

Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

2.2 Color

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

Black, Brown, 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

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Floor Tiles, Homes, Hotels, Kitchens

3.1.2 Exterior Uses

Garden Decoration

As Building Stone, Paving Stone, Garden Decoration, 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

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

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

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

4 Types

4.1 Types

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

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

4.2 Features

Blocks negativity, Helps to protect against depression

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

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

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

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet Used

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.

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.

5.2 Composition

5.2.1 Mineral Content

Not Available

Olivine, Plagioclase, Pyroxene

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

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Not Available

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.56

1 7

6.1.2 Grain Size

Not Applicable

Fine Grained

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White

White to Grey

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Vitreous

Not Available

6.1.7 Compressive Strength

0.15 N/mm²37.40 N/mm²

0.15 450

6.1.8 Cleavage

Non-Existent

Not Available

6.1.9 Toughness

Not Available

2.3

6.1.10 Specific Gravity

2.6-2.72.8-3

0 8.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³2.9-3.1 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

India, Russia

7.1.2 Africa

Kenya

South Africa

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Iceland

7.1.4 Others

Not Yet Found

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

Not Yet Found

All about Obsidian and Basalt Properties

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