Pegmatite

Nephelinite

Pegmatite and Nephelinite

Pegmatite

Nephelinite

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Definition

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

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

History

Origin

Brazil

Discoverer

R. J. Hauy

Unknown

Etymology

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

from French néphéline, from Greek nephelē

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Pegmatitic

Aphanitic

Color

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

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Layered, Banded, Veined and Shiny

Skeletal

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Paving Stone

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

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

Medical Industry

Antiquity Uses

Artifacts, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

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

Types

Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite

Peralkaline Nephelinite

Features

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

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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

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

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

Clinopyroxene, Nepheline, Plagioclase

Compound Content

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

Ca, CaO, Carbon, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Contact Metamorphism

Weathering

✔ ✘

Types of 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

76.5

1 7

👆🏻

Grain Size

Medium to Coarse Grained

Fine Grained

Fracture

Conchoidal

Flat

Streak

White

Porosity

Less Porous

Luster

Grainy, Pearly and Vitreous

Vitreous to Metallic

Compressive Strength

178.54 N/mm²35.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.1

2.7

Specific Gravity

2.6-2.632.4-2.9

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.6-2.65 g/cm³2.5-3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.79 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Japan

Africa

South Africa

Rwanda, Tanzania

Europe

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

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada

Canada, USA

South America

Brazil

Colombia

Deposits in Oceania Continent

Australia

New South Wales, Queensland, South Australia, Western Australia

All about Pegmatite and Nephelinite Properties

Know all about Pegmatite and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Pegmatite and Nephelinite belong to Igneous Rocks.Texture of Pegmatite is Pegmatitic whereas that of Nephelinite is Aphanitic. Pegmatite appears Layered, Banded, Veined and Shiny and Nephelinite appears Skeletal. The luster of Pegmatite is grainy, pearly and vitreous while that of Nephelinite is vitreous to metallic. Pegmatite and Nephelinite are available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).