Trondhjemite

Nephelinite

Trondhjemite and Nephelinite

Trondhjemite

Nephelinite

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Definition

Trondhjemite is a leucocratic (light-colored) intrusive igneous rock. It is a variety of tonalite in which the plagioclase is mostly in the form of oligoclase. Trondhjemites are sometimes known as plagiogranites.

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

History

Origin

Tonale, Italy

Brazil

Discoverer

Unknown

Etymology

From Trondheim, Norway

from French néphéline, from Greek nephelē

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Phaneritic

Aphanitic

Color

Black, Brown, Light to Dark Grey, White

Black, Brown, Green, Grey, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Banded and Foilated

Skeletal

Uses

Architecture

Interior Uses

Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

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

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Creating Artwork

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

Types

Intermediate intrusive rock

Peralkaline Nephelinite

Features

Is one of the oldest rock, Typically speckled black and white.

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

When alkali feldspar is extracted from granite, it changes to granitoid and later, it becomes trondhjemite with quartz as major mineral.

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

Albite, Amphibole, Apatite, Biotite, Feldspar, Hornblade, Ilmenite, Magnetite, Manganese Oxides, Olivine, Plagioclase, Pyroxene, Quartz, Sulfides, Titanite, Zircon

Clinopyroxene, Nepheline, Plagioclase

Compound Content

NaCl, CaO, MgO, Silicon Dioxide

Ca, CaO, Carbon, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact 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

6-76.5

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Conchoidal

Flat

Streak

Bluish Black

White

Porosity

Very Less Porous

Less Porous

Luster

Subvitreous to Dull

Vitreous to Metallic

Compressive Strength

130.00 N/mm²35.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

2.7

Specific Gravity

2.86-32.4-2.9

0 8.4

👆🏻

Transparency

Opaque

Density

2.73 g/cm³2.5-3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan

Africa

Egypt

Rwanda, Tanzania

Europe

Finland, Germany, Italy, Romania, Sweden, Turkey

Others

Hawaii Islands

Deposits in Western Continents

North America

USA

Canada, USA

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru

Colombia

Deposits in Oceania Continent

Australia

New Zealand, South Australia, Western Australia

All about Trondhjemite and Nephelinite Properties

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