Nephelinite

Dacite

Nephelinite and Dacite

Nephelinite

Dacite

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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).

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

1.2 History

1.2.1 Origin

Brazil

Romania and Moldova, Europe

1.2.2 Discoverer

Unknown

1.3 Etymology

from French néphéline, from Greek nephelē

From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Plutonic

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic

Aphanitic to Porphyritic

2.2 Color

Black, Brown, Colourless, Green, Grey, White

Bluish - Grey, Brown, Grey, Light to Dark Grey

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

Vesicular

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, Paving 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, Construction Aggregate, for Road Aggregate, Landscaping

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

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

Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Peralkaline Nephelinite

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

4.2 Features

Host Rock for Lead

Host Rock for Lead, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

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.

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

5.2 Composition

5.2.1 Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

5.2.2 Compound Content

Ca, CaO, Carbon, Cl, MgO

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Water Erosion, Wind Erosion

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.52-2.25

1 7

6.1.2 Grain Size

Fine Grained

Medium to Fine Coarse Grained

6.1.3 Fracture

Flat

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

6.1.6 Luster

Vitreous to Metallic

Subvitreous to Dull

6.1.7 Compressive Strength

35.00 N/mm²NA

0.15 450

6.1.8 Cleavage

Imperfect

Perfect

6.1.9 Toughness

2.7

Not Available

6.1.10 Specific Gravity

2.4-2.92.86-2.87

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.5-3 g/cm³2.77-2.771 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

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Japan

Not Yet Found

7.1.2 Africa

Rwanda, Tanzania

Not Yet Found

7.1.3 Europe

Not Yet Found

France, Greece, Romania, Scotland, Spain

7.1.4 Others

Hawaii Islands

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

USA

7.2.2 South America

Colombia

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New Zealand, South Australia, Western Australia

All about Nephelinite and Dacite Properties

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