Syenite

Nephelinite

Syenite and Nephelinite

Syenite

Nephelinite

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Definition

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

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

History

Origin

Brazil

Discoverer

Unknown

Etymology

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

from French néphéline, from Greek nephelē

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

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

Earthy

Aphanitic

Color

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

Flooring, Homes, Hotels, 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, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

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

Shonkinite

Peralkaline Nephelinite

Features

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

Host Rock for Lead

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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

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

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

Clinopyroxene, Nepheline, Plagioclase

Compound Content

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

Ca, CaO, Carbon, Cl, MgO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal 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

5.5-66.5

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Flat

Streak

White

Porosity

Less Porous

Luster

Subvitreous to Dull

Vitreous to Metallic

Compressive Strength

150.00 N/mm²35.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

2.7

Specific Gravity

2.6-2.72.4-2.9

0 8.4

👆🏻

Transparency

Opaque

Density

2.6-2.8 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, Impact Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Japan

Africa

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

Rwanda, Tanzania

Europe

Bulgaria, England, Germany, Norway, Romania, Switzerland

Others

Hawaii Islands

Deposits in Western Continents

North America

USA

Canada, USA

South America

Brazil, Chile

Colombia

Deposits in Oceania Continent

Australia

New Zealand, Queensland, South Australia, Western Australia

All about Syenite and Nephelinite Properties

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