Obsidian

Dolomite

Obsidian and Dolomite

Obsidian

Dolomite

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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

Dolomite is a sedimentary rock containing more than 50 percent of the mineral dolomite by weight

History

Origin

Ethiopia

Southern Alps, France

Discoverer

Obsius

Dolomieu

Etymology

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

From French, from the name of Dolomieu (1750–1801), the French geologist who discovered the rock

Class

Igneous Rocks

Sedimentary 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

Earthy

Color

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

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Shiny

Glassy or Pearly

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Garden Decoration

Garden Decoration, Office Buildings

Other Architectural Uses

Industry

Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics, Serves as an Oil and Gas Reservoir rock

Medical Industry

Surgery

Taken as a Supplement for Calcium or Magnesium

Antiquity Uses

Artifacts, Jewellery

Artifacts, Jewellery, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Mirror, Used in aquariums

An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)

Types

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

Boninite and Jasperoid

Features

Blocks negativity, Helps to protect against depression

Host Rock for Lead, Traps for subsurface fluids like Oil and Natural Gas., Zinc and Copper Deposits

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

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.

Dolomite rocks are originally deposited as calcite or aragonite rich limestone, but during diagenesis process, the calcite or aragonite is transformed into dolomite.

Composition

Mineral Content

Clay Minerals, Pyrite, Quartz, Sulfides

Compound Content

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

NaCl, CaO, Carbon Dioxide, Magnesium Carbonate, MgO

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

5-5.53.5-4

1 7

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Grain Size

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Very Less Porous

Less Porous

Luster

Vitreous

Vitreous and Pearly

Compressive Strength

0.15 N/mm²140.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

Specific Gravity

2.6-2.72.8-3

0 8.4

👆🏻

Transparency

Translucent

Transparent to Translucent

Density

2.6 g/cm³2.8-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.92 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

China, India

Africa

Kenya

Morocco, Namibia

Europe

Greece, Hungary, Iceland, Italy, Turkey

Austria, Italy, Romania, Spain, Switzerland

Others

Deposits in Western Continents

North America

Canada, Mexico, USA

Mexico, USA

South America

Argentina, Chile, Ecuador, Peru

Brazil, Colombia

Deposits in Oceania Continent

Australia

New Zealand

New South Wales, Queensland, Yorke Peninsula

All about Obsidian and Dolomite Properties

Know all about Obsidian and Dolomite properties here. All properties of rocks are important as they define the type of rock and its application. Obsidian belongs to Igneous Rocks while Dolomite belongs to Sedimentary Rocks.Texture of Obsidian is Glassy whereas that of Dolomite is Earthy. Obsidian appears Shiny and Dolomite appears Glassy or Pearly. The luster of Obsidian is vitreous while that of Dolomite is vitreous and pearly. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas Dolomite is available in black, brown, green, grey, pink, white colors. The commercial uses of Obsidian are creating artwork, mirror, used in aquariums and that of Dolomite are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).