Nephelinite

Adakite

Nephelinite and Adakite

Nephelinite

Adakite

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1 Definition

1.1 Definition

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

Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs

1.2 History

1.2.1 Origin

Brazil

Adak, Aleutian Islands

1.2.2 Discoverer

Unknown

Defant and Drummond

1.3 Etymology

from French néphéline, from Greek nephelē

From Adak, Aleutian Islands

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Plutonic

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic

Porphyritic

2.2 Color

Black, Brown, Colourless, Green, Grey, White

Black, Brown, Light to Dark Grey

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Skeletal

Dull and Soft

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens

3.1.2 Exterior Uses

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

As Building Stone, As Facing Stone, Office Buildings

3.1.3 Other Architectural Uses

Curbing

Whetstones

3.2 Industry

3.2.1 Construction Industry

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

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Monuments, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

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

Commemorative Tablets, Pottery, Used in aquariums

4 Types

4.1 Types

Peralkaline Nephelinite

Not Available

4.2 Features

Host Rock for Lead

Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

4.4 Fossils

Absent

5 Formation

5.1 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.

Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.

5.2 Composition

5.2.1 Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Olivine, Plagioclase, Pyroxene

5.2.2 Compound Content

Ca, CaO, Carbon, Cl, MgO

Aluminium Oxide, MgO, Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Contact Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Coastal Erosion, Sea Erosion, Water Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.53-4

1 7

6.1.2 Grain Size

Fine Grained

Fine to Medium Grained

6.1.3 Fracture

Flat

Conchoidal

6.1.4 Streak

White

Bluish Black

6.1.5 Porosity

Less Porous

6.1.6 Luster

Vitreous to Metallic

Grainy, Pearly and Vitreous

6.1.7 Compressive Strength

35.00 N/mm²NA

0.15 450

6.1.8 Cleavage

Imperfect

Not Available

6.1.9 Toughness

2.7

Not Available

6.1.10 Specific Gravity

2.4-2.9Not Available

0 8.4

6.1.11 Transparency

Opaque

6.1.12 Density

2.5-3 g/cm³Not Available

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.88 kJ/Kg KNA

0.14 3.2

6.2.2 Resistance

Heat Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Japan

India, Russia

7.1.2 Africa

Rwanda, Tanzania

Ethiopia, Somalia, South Africa

7.1.3 Europe

Not Yet Found

Iceland

7.1.4 Others

Hawaii Islands

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

7.2.2 South America

Colombia

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

All about Nephelinite and Adakite Properties

Know all about Nephelinite and Adakite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Adakite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Adakite is Porphyritic. Nephelinite appears Skeletal and Adakite appears Dull and Soft. The luster of Nephelinite is vitreous to metallic while that of Adakite is grainy, pearly and vitreous. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Adakite is available in black, brown, light to dark grey colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Adakite are commemorative tablets, pottery, used in aquariums.