Basalt

Pseudotachylite

Basalt and Pseudotachylite

Basalt

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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

Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.

History

Origin

Egypt

USA

Discoverer

Georgius Agricola

Unknown

Etymology

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

From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Quench

Color

Black, Brown, Light to Dark Grey

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Uses

Architecture

Interior Uses

Floor Tiles, Homes, Hotels, Kitchens

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, Garden Decoration

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

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

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

Medical Industry

Antiquity Uses

Artifacts, Monuments

Other Uses

Commercial Uses

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

Creating Artwork, Gemstone

Types

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

Cataclastic rock

Features

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

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

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

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

Compound Content

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

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Properties

Physical Properties

Hardness

1 7

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Grain Size

Fine Grained

Very fine-grained

Fracture

Conchoidal

Uneven

Streak

White to Grey

Light to dark brown

Porosity

Less Porous

Luster

Vitreous

Compressive Strength

37.40 N/mm²60.00 N/mm²

0.15 450

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Cleavage

Toughness

2.3

Specific Gravity

2.8-32.46-2.86

0 8.4

👆🏻

Transparency

Opaque

Transparent to Translucent

Density

2.9-3.1 g/cm³2.7-2.9 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

South Korea

Africa

South Africa

Western Africa

Europe

Iceland

Great Britain, Switzerland

Others

Deposits in Western Continents

North America

Canada, USA

South America

Brazil

Deposits in Oceania Continent

Australia

Central Australia, Western Australia

All about Basalt and Pseudotachylite Properties

Know all about Basalt and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Basalt belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Basalt is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Pseudotachylite is Quench. Basalt appears Dull and Soft and Pseudotachylite appears Dull and Soft. The luster of Basalt is while that of Pseudotachylite is vitreous. Basalt is available in black, brown, light to dark grey colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Basalt are an oil and gas reservoir, commemorative tablets, creating artwork, used in aquariums and that of Pseudotachylite are creating artwork, gemstone.