Nephelinite

Syenite

Nephelinite and Syenite

Nephelinite

Syenite

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Definition

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

Syenite is a coarse-grained igneous rock which is composed mainly of alkali feldspar and various ferromagnesian minerals

History

Origin

Brazil

Discoverer

Unknown

Etymology

from French néphéline, from Greek nephelē

From French syénite, from Latin Syenites (lapis ) (stone) of Syene

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

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

Texture

Aphanitic

Earthy

Color

Black, Brown, Green, Grey, White

Brown, Buff, Cream, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Skeletal

Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Flooring, Homes, Hotels, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

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

Cemetery Markers, Creating Artwork

Types

Peralkaline Nephelinite

Shonkinite

Features

Host Rock for Lead

Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable

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.

Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

Composition

Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Compound Content

Ca, CaO, Carbon, Cl, MgO

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal 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, Wind Erosion

Properties

Physical Properties

Hardness

6.55.5-6

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Flat

Streak

White

Porosity

Less Porous

Luster

Vitreous to Metallic

Subvitreous to Dull

Compressive Strength

35.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.7

Specific Gravity

2.4-2.92.6-2.7

0 8.4

👆🏻

Transparency

Opaque

Density

2.5-3 g/cm³2.6-2.8 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, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Africa

Rwanda, Tanzania

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Europe

Bulgaria, England, Germany, Norway, Romania, Switzerland

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

USA

South America

Colombia

Brazil, Chile

Deposits in Oceania Continent

Australia

New Zealand, Queensland, South Australia, Western Australia

All about Nephelinite and Syenite Properties

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