Trachyandesite

Obsidian

Trachyandesite and Obsidian

Trachyandesite

Obsidian

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Definition

Trachyandesite is an extrusive igneous rock.

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

Indonesia

Ethiopia

Discoverer

Unknown

Obsius

Etymology

From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite

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, Opaque Rock

Opaque Rock

Texture

Glassy, Massive, Porphyritic, Scoriaceous, Vesicular

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

Countertops, Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration

Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

Medical Industry

Surgery

Antiquity Uses

Artifacts, Sculpture

Artifacts, Jewellery

Other Uses

Commercial Uses

Creating Artwork, Pottery

Creating Artwork, Mirror, Used in aquariums

Types

Basaltic Trachyandesite

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

Features

Has High structural resistance against erosion and climate, 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

Trachyandesite 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

Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase

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

Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

4-55-5.5

1 7

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Grain Size

Fine Grained

Fracture

Conchoidal

Streak

Light to dark brown

White

Porosity

Less Porous

Very Less Porous

Luster

Earthy

Vitreous

Compressive Strength

37.40 N/mm²0.15 N/mm²

0.15 450

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Cleavage

Perfect

Toughness

2.3

Specific Gravity

2.8-32.6-2.7

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.9-3.1 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

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 Trachyandesite and Obsidian Properties

Know all about Trachyandesite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Trachyandesite and Obsidian belong to Igneous Rocks.Texture of Trachyandesite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Obsidian is Glassy. Trachyandesite appears Dull and Soft and Obsidian appears Shiny. The luster of Trachyandesite is earthy while that of Obsidian is vitreous. Trachyandesite 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 Trachyandesite are creating artwork, pottery and that of Obsidian are creating artwork, mirror, used in aquariums.