Nephelinite

Obsidian

Nephelinite vs Obsidian

Nephelinite

Obsidian

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Definition

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

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth

History

Origin

Brazil

Ethiopia

Discoverer

Unknown

Obsius

Etymology

from French néphéline, from Greek nephelē

From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Opaque Rock

Texture

Aphanitic

Glassy

Color

Black, Brown, Green, Grey, White

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Skeletal

Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

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

Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Medical Industry

Surgery

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Jewellery

Other Uses

Commercial Uses

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

Creating Artwork, Mirror, Used in aquariums

Types

Peralkaline Nephelinite

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

Features

Host Rock for Lead

Blocks negativity, Helps to protect against depression

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.

When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.

Composition

Mineral Content

Clinopyroxene, Nepheline, Plagioclase

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

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

Properties

Physical Properties

Hardness

6.55-5.5

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Flat

Conchoidal

Streak

White

Porosity

Less Porous

Very Less Porous

Luster

Vitreous to Metallic

Vitreous

Compressive Strength

35.00 N/mm²0.15 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.7

Specific Gravity

2.4-2.92.6-2.7

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.5-3 g/cm³2.6 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

Reserves

Deposits in Eastern Continents

Asia

Japan

Afghanistan, Indonesia, Japan, Russia

Africa

Rwanda, Tanzania

Kenya

Europe

Greece, Hungary, Iceland, Italy, Turkey

Others

Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

Canada, Mexico, USA

South America

Colombia

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

Nephelinite vs Obsidian Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Nephelinite and Obsidian Reserves. Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).. Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Nephelinite vs Obsidian information and Nephelinite vs Obsidian characteristics in the upcoming sections.

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Nephelinite vs Obsidian Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Nephelinite vs Obsidian characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Nephelinite and Properties of Obsidian. Learn more about Nephelinite vs Obsidian in the next section. The interior uses of Nephelinite include Decorative aggregates, Homes and Interior decoration whereas the interior uses of Obsidian include Decorative aggregates and Interior decoration. Due to some exceptional properties of Nephelinite and Obsidian, they have various applications in construction industry. The uses of Nephelinite in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate and that of Obsidian include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.

More about Nephelinite and Obsidian

Here you can know more about Nephelinite and Obsidian. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Nephelinite and Obsidian consists of mineral content and compound content. The mineral content of Nephelinite includes Clinopyroxene, Nepheline, Plagioclase and mineral content of Obsidian includes . You can also check out the list of all Igneous Rocks. When we have to compare Nephelinite vs Obsidian, the texture, color and appearance plays an important role in determining the type of rock. Nephelinite is available in black, brown, green, grey, white colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Nephelinite is Skeletal and that of Obsidian is Shiny. Properties of rock is another aspect for Nephelinite vs Obsidian. The hardness of Nephelinite is 6.5 and that of Obsidian is 5-5.5. The types of Nephelinite are Peralkaline Nephelinite whereas types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Nephelinite and Obsidian is white. The specific heat capacity of Nephelinite is 0.88 kJ/Kg K and that of Obsidian is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Nephelinite is heat resistant whereas Obsidian is heat resistant, impact resistant.