Basalt

Porphyry

Basalt and Porphyry

Basalt

Porphyry

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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

Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix

History

Origin

Egypt

Discoverer

Georgius Agricola

Unknown

Etymology

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

From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Porphyritic

Color

Black, Brown, Light to Dark Grey

Black, Brown, Green, Grey, Red, Rust, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Dull

Uses

Architecture

Interior Uses

Floor Tiles, Homes, Hotels, Kitchens

Decorative Aggregates, Interior Decoration

Exterior Uses

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

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

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

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

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

Creating Artwork, Gemstone, Jewelry

Types

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

Rhomb Porphyry

Features

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

Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny

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.

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

Compound Content

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

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

66-7

1 7

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Grain Size

Fine Grained

Fracture

Conchoidal

Irregular

Streak

White to Grey

White

Porosity

Less Porous

Luster

Dull

Compressive Strength

37.40 N/mm²150.00 N/mm²

0.15 450

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Cleavage

Toughness

2.3

1.7

Specific Gravity

2.8-32.5-4

0 8.4

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Transparency

Opaque

Translucent to Opaque

Density

2.9-3.1 g/cm³2.5-2.52 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam

Africa

South Africa

Egypt, Ethiopia, Ghana, South Africa

Europe

Iceland

Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland

Others

Greenland

Deposits in Western Continents

North America

Canada, USA

Canada, Cuba, Jamaica, USA

South America

Brazil

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

All about Basalt and Porphyry Properties

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