Obsidian

Shoshonite

Obsidian and Shoshonite

Obsidian

Shoshonite

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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

Shoshonite is a basaltic rock, properly a potassic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored volcanic glass

History

Origin

Ethiopia

Wyoming,USA

Discoverer

Obsius

Iddings

Etymology

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

From the place of origin called Shoshone riverin Wyoming

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Glassy

Porphyritic

Color

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

Brown- Black, Dark Brown

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Garden Decoration

As Building Stone, As Facing 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

Sculpture

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Cemetery Markers, Creating Artwork

Types

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

Intermediate volcanic rock

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.

Shoshonite 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

Pyroxene

Compound Content

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

Aluminium Oxide, Iron(III) Oxide, Potassium Oxide, Sodium Oxide, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of 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, Glacier Erosion

Properties

Physical Properties

Hardness

5-5.56

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Uneven

Streak

White

White to Grey

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Dull

Compressive Strength

0.15 N/mm²175.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.6

Specific Gravity

2.6-2.72.98

0 8.4

👆🏻

Transparency

Translucent

Opaque

Density

2.6 g/cm³2.9-3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure 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

All about Obsidian and Shoshonite Properties

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