Nephelinite

Pseudotachylite

Nephelinite and Pseudotachylite

Nephelinite

Pseudotachylite

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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).

Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.

1.2 History

1.2.1 Origin

Brazil

USA

1.2.2 Discoverer

Unknown

1.3 Etymology

from French néphéline, from Greek nephelē

From pseudo- +‎ tachylite, a glassy rock generated by frictional heat within faults.

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Plutonic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic

Quench

2.2 Color

Black, Brown, Colourless, Green, Grey, White

Black, Brown, Colourless, Green, Grey, Pink, White

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, Entryways, Interior Decoration

3.1.2 Exterior Uses

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

As Building Stone, As Facing Stone, Garden Decoration

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

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

As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

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

Creating Artwork, Gemstone

4 Types

4.1 Types

Peralkaline Nephelinite

Not Available

4.2 Features

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Used

Not Yet 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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

5.2 Composition

5.2.1 Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides

5.2.2 Compound Content

Ca, CaO, Carbon, Cl, MgO

Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.57

1 7

6.1.2 Grain Size

Fine Grained

Very fine-grained

6.1.3 Fracture

Flat

Uneven

6.1.4 Streak

White

Light to dark brown

6.1.5 Porosity

Less Porous

6.1.6 Luster

Vitreous to Metallic

Vitreous

6.1.7 Compressive Strength

35.00 N/mm²60.00 N/mm²

0.15 450

6.1.8 Cleavage

Imperfect

Irregular

6.1.9 Toughness

2.7

Not Available

6.1.10 Specific Gravity

2.4-2.92.46-2.86

0 8.4

6.1.11 Transparency

Opaque

Transparent to Translucent

6.1.12 Density

2.5-3 g/cm³2.7-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.88 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Japan

South Korea

7.1.2 Africa

Rwanda, Tanzania

Western Africa

7.1.3 Europe

Not Yet Found

Great Britain, Switzerland

7.1.4 Others

Hawaii Islands

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Not Yet Found

7.2.2 South America

Colombia

Not Yet Found

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

Central Australia, Western Australia

All about Nephelinite and Pseudotachylite Properties

Know all about Nephelinite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Nephelinite is Aphanitic whereas that of Pseudotachylite is Quench. Nephelinite appears Skeletal and Pseudotachylite appears Dull and Soft. The luster of Nephelinite is vitreous to metallic while that of Pseudotachylite is vitreous. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Pseudotachylite are creating artwork, gemstone.