Nephelinite

Dunite

Nephelinite and Dunite

Nephelinite

Dunite

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Definition

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

Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine

History

Origin

Brazil

New Zealand

Discoverer

Unknown

Ferdinand von Hochstetter

Etymology

from French néphéline, from Greek nephelē

From the name of Dun Mountain, New Zealand, + -ite1

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Aphanitic

Phaneritic

Color

Black, Brown, Green, Grey, White

Dark Greenish - Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Skeletal

Rough and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds

Types

Peralkaline Nephelinite

Dunite

Features

Host Rock for Lead

Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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.

Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.

Composition

Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene

Compound Content

Ca, CaO, Carbon, Cl, MgO

Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Properties

Physical Properties

Hardness

6.53.5-4

1 7

👆🏻

Grain Size

Fine Grained

Coarse Grained

Fracture

Flat

Irregular

Streak

White

Porosity

Less Porous

Luster

Vitreous to Metallic

Shiny

Compressive Strength

35.00 N/mm²107.55 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.7

2.1

Specific Gravity

2.4-2.93-3.01

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

2.5-3 g/cm³2.84-2.85 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.88 kJ/Kg K1.25 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan

China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey

Africa

Rwanda, Tanzania

Morocco, South Africa

Europe

Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

South America

Colombia

Argentina, Brazil, Colombia, Ecuador, Venezuela

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

All about Nephelinite and Dunite Properties

Know all about Nephelinite and Dunite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Dunite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Dunite is Phaneritic. Nephelinite appears Skeletal and Dunite appears Rough and Shiny. The luster of Nephelinite is vitreous to metallic while that of Dunite is shiny. Nephelinite is available in black, brown, green, grey, white colors whereas Dunite is available in dark greenish - grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Dunite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.