Dunite

Nephelinite

Dunite and Nephelinite

Dunite

Nephelinite

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Definition

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

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

History

Origin

New Zealand

Brazil

Discoverer

Ferdinand von Hochstetter

Unknown

Etymology

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

from French néphéline, from Greek nephelē

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Phaneritic

Aphanitic

Color

Dark Greenish - Grey

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

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

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

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

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

Types

Dunite

Peralkaline Nephelinite

Features

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

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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

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

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

Clinopyroxene, Nepheline, Plagioclase

Compound Content

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

Ca, CaO, Carbon, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

3.5-46.5

1 7

👆🏻

Grain Size

Coarse Grained

Fine Grained

Fracture

Irregular

Flat

Streak

White

Porosity

Less Porous

Luster

Shiny

Vitreous to Metallic

Compressive Strength

107.55 N/mm²35.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

2.7

Specific Gravity

3-3.012.4-2.9

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.84-2.85 g/cm³2.5-3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

1.25 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

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

Japan

Africa

Morocco, South Africa

Rwanda, Tanzania

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

Argentina, Brazil, Colombia, Ecuador, Venezuela

Colombia

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

All about Dunite and Nephelinite Properties

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