Basalt

Picrite

Basalt and Picrite

Basalt

Picrite

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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

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

History

Origin

Egypt

Hawaii Islands

Discoverer

Georgius Agricola

Unknown

Etymology

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

From Greek pikros bitter + -ite, 19th century

Class

Igneous 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

Earthy, Rough

Color

Black, Brown, Light to Dark Grey

Black, Brown, Green, Grey, Pink, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Rough and Shiny

Uses

Architecture

Interior Uses

Floor Tiles, Homes, Hotels, Kitchens

Countertops, Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

Other Architectural Uses

Curbing, Whetstones

Curbing

Industry

Construction Industry

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

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

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

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

Types

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

Oceanite

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.

Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

Biotite, Olivine, Plagioclase, Pyrrhotite

Compound Content

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

Al, CaO, Carbon Dioxide, Mg, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

66.8

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Conchoidal

Uneven

Streak

White to Grey

White, Greenish White or Grey

Porosity

Less Porous

Luster

Subvitreous to Dull

Compressive Strength

37.40 N/mm²189.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.3

2.1

Specific Gravity

2.8-32.75-2.92

0 8.4

👆🏻

Transparency

Opaque

Density

2.9-3.1 g/cm³1.5-2.5 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Africa

South Africa

Europe

Iceland

Others

Deposits in Western Continents

North America

Canada, USA

South America

Brazil

Deposits in Oceania Continent

Australia

All about Basalt and Picrite Properties

Know all about Basalt and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Basalt and Picrite belong to Igneous Rocks.Texture of Basalt is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Picrite is Earthy, Rough. Basalt appears Dull and Soft and Picrite appears Rough and Shiny. The luster of Basalt is while that of Picrite is subvitreous to dull. Basalt is available in black, brown, light to dark grey colors whereas Picrite is available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Basalt are an oil and gas reservoir, commemorative tablets, creating artwork, used in aquariums and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).