Dacite

Nephelinite

Dacite and Nephelinite

Dacite

Nephelinite

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1 Definition

1.1 Definition

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

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

1.3 History

1.3.1 Origin

Romania and Moldova, Europe

Brazil

1.3.4 Discoverer

Unknown

1.4 Etymology

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

from French néphéline, from Greek nephelē

1.5 Class

Igneous Rocks

1.6.2 Sub-Class

Durable Rock, Soft Rock

Durable Rock, Hard Rock

1.7 Family

1.7.1 Group

Volcanic

Plutonic

1.9 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic to Porphyritic

Aphanitic

2.2 Color

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

Black, Brown, Colourless, Green, Grey, White

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

Vesicular

Skeletal

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Entryways, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, Paving Stone, Garden Decoration

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

3.4 Other Uses

3.4.1 Commercial Uses

Commemorative Tablets, Creating Artwork

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

4 Types

4.1 Types

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Peralkaline Nephelinite

4.2 Features

Host Rock for Lead, Is one of the oldest rock

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

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.

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.

5.2 Composition

5.2.1 Mineral Content

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

Clinopyroxene, Nepheline, Plagioclase

5.2.2 Compound Content

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

Ca, CaO, Carbon, Cl, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Contact 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

Chemical Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

2-2.256.5

1 7

6.1.2 Grain Size

Medium to Fine Coarse Grained

Fine Grained

6.1.3 Fracture

Conchoidal

Flat

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

6.1.6 Luster

Subvitreous to Dull

Vitreous to Metallic

6.1.7 Compressive Strength

NA35.00 N/mm²

0.15 450

6.1.8 Cleavage

Perfect

Imperfect

6.1.9 Toughness

Not Available

2.7

6.1.10 Specific Gravity

2.86-2.872.4-2.9

0 8.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.77-2.771 g/cm³2.5-3 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Not Yet Found

Japan

7.1.2 Africa

Not Yet Found

Rwanda, Tanzania

7.1.3 Europe

France, Greece, Romania, Scotland, Spain

Not Yet Found

7.1.4 Others

Not Yet Found

Hawaii Islands

7.2 Deposits in Western Continents

7.2.1 North America

USA

Canada, USA

7.2.2 South America

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

Colombia

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand, South Australia, Western Australia

Not Yet Found

All about Dacite and Nephelinite Properties

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