Obsidian

Epidosite

Obsidian vs Epidosite

Obsidian

Epidosite

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Definition

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

Epidosite is a highly altered epidote and quartz bearing rock which is a type of metasomatite, essentially altered basalt

History

Origin

Ethiopia

Discoverer

Obsius

Unknown

Etymology

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Opaque Rock

Texture

Glassy

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

Color

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

Black, Brown, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Hotels, Interior Decoration

Exterior Uses

Garden Decoration

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Medical Industry

Surgery

Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Commemorative Tablets, Creating Artwork

Types

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

Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite

Features

Blocks negativity, Helps to protect against depression

Has High structural resistance against erosion and climate, Very fine grained rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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.

Epidosite 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

Olivine, Plagioclase, Pyroxene

Compound Content

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

5-5.56

1 7

👆🏻

Grain Size

Fine to Coarse Grained

Fracture

Conchoidal

Streak

White

White to Grey

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Compressive Strength

0.15 N/mm²160.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.3

Specific Gravity

2.6-2.72.8-3

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.6 g/cm³-9999 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

India, Russia

Africa

Kenya

South Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

Iceland

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Argentina, Chile, Ecuador, Peru

Brazil

Deposits in Oceania Continent

Australia

New Zealand

Obsidian vs Epidosite 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 Obsidian and Epidosite Reserves. 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. Epidosite is a highly altered epidote and quartz bearing rock which is a type of metasomatite, essentially altered basalt. 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 Obsidian vs Epidosite information and Obsidian vs Epidosite characteristics in the upcoming sections.

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Obsidian vs Epidosite 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. Obsidian vs Epidosite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Epidosite. Learn more about Obsidian vs Epidosite in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Epidosite include Decorative aggregates, Floor tiles, Homes, Hotels and Interior decoration. Due to some exceptional properties of Obsidian and Epidosite, they have various applications in construction industry. The uses of Obsidian in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Epidosite include As dimension stone, Cobblestones, Rail track ballast, Roadstone.

More about Obsidian and Epidosite

Here you can know more about Obsidian and Epidosite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Epidosite consists of mineral content and compound content. The mineral content of Obsidian includes and mineral content of Epidosite includes Olivine, Plagioclase, Pyroxene. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Epidosite, the texture, color and appearance plays an important role in determining the type of rock. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas, Epidosite is available in black, brown, light to dark grey colors. Appearance of Obsidian is Shiny and that of Epidosite is Dull and Soft. Properties of rock is another aspect for Obsidian vs Epidosite. The hardness of Obsidian is 5-5.5 and that of Epidosite is 6. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Epidosite are Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian is white while that of Epidosite is white to grey. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Epidosite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Obsidian is heat resistant, impact resistant whereas Epidosite is heat resistant, pressure resistant, wear resistant.