Picrite

Nephelinite

Picrite and Nephelinite

Picrite

Nephelinite

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Definition

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

Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).

History

Origin

Hawaii Islands

Brazil

Discoverer

Unknown

Etymology

From Greek pikros bitter + -ite, 19th century

from French néphéline, from Greek nephelē

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Earthy, Rough

Aphanitic

Color

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

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Rough and Shiny

Skeletal

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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.

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)

Types

Oceanite

Peralkaline Nephelinite

Features

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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.

Nephelinite 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

Biotite, Olivine, Plagioclase, Pyrrhotite

Clinopyroxene, Nepheline, Plagioclase

Compound Content

Al, CaO, Carbon Dioxide, Mg, MgO

Ca, CaO, Carbon, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

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

Chemical Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6.86.5

1 7

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Grain Size

Fine Grained

Fracture

Uneven

Flat

Streak

White, Greenish White or Grey

White

Porosity

Less Porous

Luster

Subvitreous to Dull

Vitreous to Metallic

Compressive Strength

189.00 N/mm²35.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

2.7

Specific Gravity

2.75-2.922.4-2.9

0 8.4

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Transparency

Opaque

Density

1.5-2.5 g/cm³2.5-3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.88 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Japan

Africa

South Africa

Rwanda, Tanzania

Europe

Iceland

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

South America

Brazil

Colombia

Deposits in Oceania Continent

Australia

All about Picrite and Nephelinite Properties

Know all about Picrite and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite and Nephelinite belong to Igneous Rocks.Texture of Picrite is Earthy, Rough whereas that of Nephelinite is Aphanitic. Picrite appears Rough and Shiny and Nephelinite appears Skeletal. The luster of Picrite is subvitreous to dull while that of Nephelinite is vitreous to metallic. Picrite and Nephelinite are available in black, brown, green, grey, pink, white, yellow colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).