Dunite and Pegmatite

Dunite

Pegmatite

Pegmatite and Dunite

Definition

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

Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals

History

Origin

New Zealand

Unknown

Discoverer

Ferdinand von Hochstetter

R. J. Hauy

Etymology

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

From Greek pegma, pegmat which means- thing joined together + -ite

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Texture

Phaneritic

Pegmatitic

Color

Dark Greenish - Grey

Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Yes

Wind Resistant

Acid Resistant

Appearance

Rough and Shiny

Layered, Banded, Veined and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

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

As Building Stone, As Facing Stone, 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, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz

Types

Not Available

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Features

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

Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz

Archaeological Significance

Monuments

Used

Not Yet Used

Famous Monuments

Data Not Available

Not Applicable

Sculpture

Used

Famous Sculptures

Data Not Available

Pictographs

Used

Not Used

Petroglyphs

Used

Not Used

Figurines

Used

Fossils

Absent

Formation

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

Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.

Composition

Mineral Content

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

Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz

Compound Content

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

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide

Transformation

Metamorphism

Yes

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

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

Weathering

Yes

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

Yes

Types of Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

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

Properties

Physical Properties

Hardness

3.5-4

Grain Size

Coarse Grained

Medium to Coarse Grained

Fracture

Irregular

Conchoidal

Streak

White

Porosity

Less Porous

Luster

Shiny

Grainy, Pearly and Vitreous

Compressive Strength

107.55 N/mm²

178.54 N/mm²

Cleavage

Imperfect

Perfect

Toughness

2.1

Specific Gravity

3-3.01

2.6-2.63

Transparency

Translucent to Opaque

Density

2.84-2.85 g/cm³

2.6-2.65 g/cm³

Thermal Properties

Specific Heat Capacity

1.25 kJ/Kg K

Not Available

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea

Africa

Morocco, South Africa

South Africa

Europe

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

Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine

Others

Not Yet Found

Deposits in Western Continents

North America

Canada, USA

Canada

South America

Argentina, Brazil, Colombia, Ecuador, Venezuela

Brazil

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New South Wales, Queensland, South Australia, Western Australia

Summary >>

<< Reserves

All about Dunite and Pegmatite Properties

Know all about Dunite and Pegmatite properties here. All properties of rocks are important as they define the type of rock and its application. Dunite and Pegmatite belong to Igneous Rocks.Texture of Dunite is Phaneritic whereas that of Pegmatite is Pegmatitic. Dunite appears Rough and Shiny and Pegmatite appears Layered, Banded, Veined and Shiny. The luster of Dunite is shiny while that of Pegmatite is grainy, pearly and vitreous. Dunite is available in dark greenish - grey colors whereas Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Dunite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds and that of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz.