Nephelinite

Chert

Nephelinite and Chert

Nephelinite

Chert

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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).

Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture

1.2 History

1.2.1 Origin

Brazil

Unknown

1.2.2 Discoverer

Unknown

1.3 Etymology

from French néphéline, from Greek nephelē

From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use

1.4 Class

Igneous Rocks

Sedimentary Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Plutonic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Aphanitic

Banded, Rough

2.2 Color

Black, Brown, Colourless, Green, Grey, White

Black, Brown, Green, Grey, Red, 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

Skeletal

Glassy or Pearly

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Homes

3.1.2 Exterior Uses

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

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

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

Arrowheads, Construction Aggregate, Cutting Tool, Spear Points

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

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

Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms

4 Types

4.1 Types

Peralkaline Nephelinite

Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter

4.2 Features

Host Rock for Lead

Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

Present

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.

Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.

5.2 Composition

5.2.1 Mineral Content

Clinopyroxene, Nepheline, Plagioclase

Quartz, Silicon

5.2.2 Compound Content

Ca, CaO, Carbon, Cl, MgO

Silicon Dioxide

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Contact Metamorphism

Not Applicable

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Not Applicable

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

6.56.5-7

1 7

6.1.2 Grain Size

Fine Grained

Very fine-grained

6.1.3 Fracture

Flat

Uneven, Splintery or Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Vitreous to Metallic

Waxy and Dull

6.1.7 Compressive Strength

35.00 N/mm²450.00 N/mm²

0.15 450

6.1.8 Cleavage

Imperfect

Non-Existent

6.1.9 Toughness

2.7

1.5

6.1.10 Specific Gravity

2.4-2.92.5-2.8

0 8.4

6.1.11 Transparency

Opaque

Translucent to Opaque

6.1.12 Density

2.5-3 g/cm³2.7 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.88 kJ/Kg K0.74 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

China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam

7.1.2 Africa

Rwanda, Tanzania

Kenya, Morocco, South Africa, Tanzania

7.1.3 Europe

Not Yet Found

Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom

7.1.4 Others

Hawaii Islands

Greenland, Mid-Atlantic Ridge

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Mexico, USA

7.2.2 South America

Colombia

Bolivia, Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New South Wales, Queensland, South Australia, Western Australia

All about Nephelinite and Chert Properties

Know all about Nephelinite and Chert properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite belongs to Igneous Rocks while Chert belongs to Sedimentary Rocks.Texture of Nephelinite is Aphanitic whereas that of Chert is Banded, Rough. Nephelinite appears Skeletal and Chert appears Glassy or Pearly. The luster of Nephelinite is vitreous to metallic while that of Chert is waxy and dull. Nephelinite is available in black, brown, colourless, green, grey, white colors whereas Chert is available in black, brown, green, grey, red, white colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms.