Basalt

Dacite

Basalt and Dacite

Basalt

Dacite

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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

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

History

Origin

Egypt

Romania and Moldova, Europe

Discoverer

Georgius Agricola

Unknown

Etymology

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

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Aphanitic to Porphyritic

Color

Black, Brown, Light to Dark Grey

Bluish - Grey, Brown, Grey, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Vesicular

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, Paving 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, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts

Other Uses

Commercial Uses

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

Commemorative Tablets, Creating Artwork

Types

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

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

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

Host Rock for Lead, Is one of the oldest rock

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.

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Compound Content

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

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

62-2.25

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White to Grey

White

Porosity

Less Porous

Luster

Subvitreous to Dull

Compressive Strength

37.40 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.3

Specific Gravity

2.8-32.86-2.87

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.9-3.1 g/cm³2.77-2.771 g/cm³

0 1400

👆🏻

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, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Africa

South Africa

Europe

Iceland

France, Greece, Romania, Scotland, Spain

Others

Deposits in Western Continents

North America

Canada, USA

USA

South America

Brazil

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

All about Basalt and Dacite Properties

Know all about Basalt and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Basalt and Dacite belong to Igneous Rocks.Texture of Basalt is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Dacite is Aphanitic to Porphyritic. Basalt appears Dull and Soft and Dacite appears Vesicular. The luster of Basalt is while that of Dacite is subvitreous to dull. Basalt is available in black, brown, light to dark grey colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Basalt and Dacite are an oil and gas reservoir, commemorative tablets, creating artwork, used in aquariums.