Adakite

Obsidian

Adakite and Obsidian

Adakite

Obsidian

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Definition

Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs

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

Adak, Aleutian Islands

Ethiopia

Discoverer

Defant and Drummond

Obsius

Etymology

From Adak, Aleutian Islands

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

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Opaque Rock

Texture

Porphyritic

Glassy

Color

Black, Brown, Light to Dark Grey

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Office Buildings

Garden Decoration

Other Architectural Uses

Whetstones

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Medical Industry

Surgery

Antiquity Uses

Monuments, Sculpture, Small Figurines

Artifacts, Jewellery

Other Uses

Commercial Uses

Commemorative Tablets, Pottery, Used in aquariums

Creating Artwork, Mirror, Used in aquariums

Types

Intermediate volcanic rock

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

Features

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

Blocks negativity, Helps to protect against depression

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.

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

Olivine, Plagioclase, Pyroxene

Compound Content

Aluminium Oxide, MgO, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Sea Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

3-45-5.5

1 7

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Grain Size

Fine to Medium Grained

Fracture

Conchoidal

Streak

Bluish Black

White

Porosity

Less Porous

Very Less Porous

Luster

Grainy, Pearly and Vitreous

Vitreous

Compressive Strength

200.00 N/mm²0.15 N/mm²

0.15 450

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Cleavage

Toughness

Specific Gravity

-99992.6-2.7

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

-9999 g/cm³2.6 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

Afghanistan, Indonesia, Japan, Russia

Africa

Ethiopia, Somalia, South Africa

Kenya

Europe

Iceland

Greece, Hungary, Iceland, Italy, Turkey

Others

Deposits in Western Continents

North America

Canada, USA

Canada, Mexico, USA

South America

Brazil

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

All about Adakite and Obsidian Properties

Know all about Adakite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Adakite and Obsidian belong to Igneous Rocks.Texture of Adakite is Porphyritic whereas that of Obsidian is Glassy. Adakite appears Dull and Soft and Obsidian appears Shiny. The luster of Adakite is grainy, pearly and vitreous while that of Obsidian is vitreous. Adakite is available in black, brown, light to dark grey colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Adakite are commemorative tablets, pottery, used in aquariums and that of Obsidian are creating artwork, mirror, used in aquariums.