Obsidian

Harzburgite

Obsidian and Harzburgite

Obsidian

Harzburgite

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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

Harzburgite is a plutonic rock of the peridotite group consisting largely of orthopyroxene and olivine

History

Origin

Ethiopia

Germany

Discoverer

Obsius

Unknown

Etymology

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

From the name of a town in Harzburg, Germany

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Plutonic

Other Categories

Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Glassy

Phaneritic

Color

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

Dark Greenish - Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Rough and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Garden Decoration

As Building Stone, 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

Medical Industry

Surgery

Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds

Types

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

Ultramafic rock

Features

Blocks negativity, Helps to protect against depression

Constitutes upper part of the Earth's mantle, Generally rough to touch, Is one of the oldest 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.

Harzburgite 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

Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene

Compound Content

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

Ca, Fe, Mg, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Sea Erosion

Properties

Physical Properties

Hardness

5-5.55.5-6

1 7

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Grain Size

Coarse Grained

Fracture

Conchoidal

Irregular

Streak

White

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Shiny

Compressive Strength

0.15 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

2.1

Specific Gravity

2.6-2.73-3.01

0 8.4

👆🏻

Transparency

Translucent

Translucent to Opaque

Density

2.6 g/cm³3.1-3.4 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K1.25 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

Japan, Oman

Africa

Kenya

South Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

France, Germany, Italy

Others

Hawaii Islands, Mid-Atlantic Ridge

Deposits in Western Continents

North America

Canada, Mexico, USA

Canada, USA

South America

Argentina, Chile, Ecuador, Peru

Deposits in Oceania Continent

Australia

New Zealand

All about Obsidian and Harzburgite Properties

Know all about Obsidian and Harzburgite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian and Harzburgite belong to Igneous Rocks.Texture of Obsidian is Glassy whereas that of Harzburgite is Phaneritic. Obsidian appears Shiny and Harzburgite appears Rough and Shiny. The luster of Obsidian is vitreous while that of Harzburgite is shiny. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Harzburgite is available in dark greenish - grey colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Harzburgite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.