Obsidian

Picrite

Obsidian vs Picrite

Obsidian

Picrite

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1 Definition

1.1 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

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

1.2 History

1.2.1 Origin

Ethiopia

Hawaii Islands

1.2.2 Discoverer

Obsius

Unknown

1.3 Etymology

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

From Greek pikros bitter + -ite, 19th century

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

1.6 Other Categories

Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Glassy

Earthy, Rough

2.2 Color

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

Black, Brown, Colourless, Green, Grey, Pink, White, Yellow

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Shiny

Rough and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

3.1.3 Other Architectural Uses

Not Yet Used

Curbing

3.2 Industry

3.2.1 Construction Industry

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

3.2.2 Medical Industry

Surgery

Not Yet Used

3.3 Antiquity Uses

Artifacts, Jewellery

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Mirror, Used in aquariums

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

4 Types

4.1 Types

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

Oceanite

4.2 Features

Blocks negativity, Helps to protect against depression

Host Rock for Lead

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

5 Formation

5.1 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.

Picrite 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.

5.2 Composition

5.2.1 Mineral Content

Not Available

Biotite, Olivine, Plagioclase, Pyrrhotite

5.2.2 Compound Content

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

Al, CaO, Carbon Dioxide, Mg, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

5-5.56.8

1 7

6.1.2 Grain Size

Not Applicable

Fine Grained

6.1.3 Fracture

Conchoidal

Uneven

6.1.4 Streak

White

White, Greenish White or Grey

6.1.5 Porosity

Very Less Porous

Less Porous

6.1.6 Luster

Vitreous

Subvitreous to Dull

6.1.7 Compressive Strength

0.15 N/mm²189.00 N/mm²

0.15 450

6.1.8 Cleavage

Non-Existent

Imperfect

6.1.9 Toughness

Not Available

2.1

6.1.10 Specific Gravity

2.6-2.72.75-2.92

0 8.4

6.1.11 Transparency

Translucent

Opaque

6.1.12 Density

2.6 g/cm³1.5-2.5 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.92 kJ/Kg K0.88 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

Afghanistan, Indonesia, Japan, Russia

India, Russia

7.1.2 Africa

Kenya

South Africa

7.1.3 Europe

Greece, Hungary, Iceland, Italy, Turkey

Iceland

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Mexico, USA

Canada, USA

7.2.2 South America

Argentina, Chile, Ecuador, Peru

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New Zealand

Not Yet Found

Obsidian vs Picrite Information

Earth’s outer layer is covered by rocks and these rocks have different physical and chemical properties. As two rocks are not same, it’s fun to compare them. You can also know more about Obsidian and Picrite Reserves. 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. Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks. Rocks are quarried from many years for various purposes. You can check out Obsidian vs Picrite information and Obsidian vs Picrite characteristics in the upcoming sections.

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Obsidian vs Picrite Characteristics

Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Obsidian vs Picrite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Obsidian and Properties of Picrite. Learn more about Obsidian vs Picrite in the next section. The interior uses of Obsidian include Decorative aggregates and Interior decoration whereas the interior uses of Picrite include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Obsidian and Picrite, they have various applications in construction industry. The uses of Obsidian in construction industry include Arrowheads, Cutting tool, Knives, Scrapers, Spear points and that of Picrite include As a sintering agent in steel industry to process iron ore, Cement manufacture, For road aggregate, Manufacture of magnesium and dolomite refractories, Roadstone, Used for flooring, stair treads, borders and window sills..

More about Obsidian and Picrite

Here you can know more about Obsidian and Picrite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Obsidian and Picrite consists of mineral content and compound content. The mineral content of Obsidian is not available and mineral content of Picrite includes Biotite, Olivine, Plagioclase, Pyrrhotite. You can also check out the list of all Igneous Rocks. When we have to compare Obsidian vs Picrite, the texture, color and appearance plays an important role in determining the type of rock. Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors whereas, Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors. Appearance of Obsidian is Shiny and that of Picrite is Rough and Shiny. Properties of rock is another aspect for Obsidian vs Picrite. The hardness of Obsidian is 5-5.5 and that of Picrite is 6.8. The types of Obsidian are Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian whereas types of Picrite are Oceanite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Obsidian is white while that of Picrite is white, greenish white or grey. The specific heat capacity of Obsidian is 0.92 kJ/Kg K and that of Picrite is 0.88 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Obsidian is heat resistant, impact resistant whereas Picrite is heat resistant.