Nephelinite

Tephrite

Nephelinite and Tephrite

Nephelinite

Tephrite

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Definition

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

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

History

Origin

Brazil

Germany

Discoverer

Unknown

Van Tooren

Etymology

from French néphéline, from Greek nephelē

From Greek tephra, ashes from Indo-European base, to burn

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Aphanitic

Aphanitic to Porphyritic

Color

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Skeletal

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Landscaping

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Sculpture

Other Uses

Commercial Uses

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

Production of Lime, Soil Conditioner

Types

Peralkaline Nephelinite

Igneous rock

Features

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

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.

Tephrite 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

Clinopyroxene, Nepheline, Plagioclase

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

Compound Content

Ca, CaO, Carbon, Cl, MgO

CaO, Carbon Dioxide, MgO, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

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

Properties

Physical Properties

Hardness

6.56.5

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Flat

Uneven

Streak

White

Bluish Black

Porosity

Less Porous

Very Less Porous

Luster

Vitreous to Metallic

Subvitreous to Dull

Compressive Strength

35.00 N/mm²90.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

2.7

2.4

Specific Gravity

2.4-2.92.86

0 8.4

👆🏻

Transparency

Opaque

Density

2.5-3 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.88 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan

Africa

Rwanda, Tanzania

Namibia, Uganda

Europe

Germany, Hungary, Italy, Portugal, Spain

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

USA

South America

Colombia

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

All about Nephelinite and Tephrite Properties

Know all about Nephelinite and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Tephrite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Tephrite is Aphanitic to Porphyritic. Nephelinite appears Skeletal and Tephrite appears Vesicular. The luster of Nephelinite is vitreous to metallic while that of Tephrite is subvitreous to dull. Nephelinite and Tephrite are available in black, brown, green, grey, white colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Tephrite are production of lime, soil conditioner.