Rapakivi Granite

Obsidian

Rapakivi Granite and Obsidian

Rapakivi Granite

Obsidian

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1 Definition

1.1 Definition

Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase

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

1.2 History

1.2.1 Origin

Finland, Europe

Ethiopia

1.2.2 Discoverer

Jakob Sederholm

Obsius

1.3 Etymology

From Finnish Rapakivi which stands for crumbly rock

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

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Plutonic

Volcanic

1.6 Other Categories

Coarse Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Granular, Phaneritic

Glassy

2.2 Color

Black, Grey, Orange, Pink, White

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

Veined or Pebbled

Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

As Building Stone, As Facing Stone, Office Buildings, Paving Stone, Resorts

Garden Decoration

3.1.3 Other Architectural Uses

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Laboratory bench tops, Tombstones

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite

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

4.2 Features

Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock

Blocks negativity, Helps to protect against depression

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental 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.

5.2 Composition

5.2.1 Mineral Content

Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Not Available

5.2.2 Compound Content

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-75-5.5

1 7

6.1.2 Grain Size

Large and Coarse Grained

Not Applicable

6.1.3 Fracture

Not Available

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

Very Less Porous

6.1.6 Luster

Dull to Grainy with Sporadic parts Pearly and Vitreous

Vitreous

6.1.7 Compressive Strength

175.00 N/mm²0.15 N/mm²

0.15 450

6.1.8 Cleavage

Not Available

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.6-2.72.6-2.7

0 8.4

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

2.6-2.8 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.79 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Wear Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Kenya

7.1.3 Europe

Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic, Venezuela

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Mexico, USA

7.2.2 South America

Not Yet Found

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New Zealand

All about Rapakivi Granite and Obsidian Properties

Know all about Rapakivi Granite and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Rapakivi Granite and Obsidian belong to Igneous Rocks.Texture of Rapakivi Granite is Granular, Phaneritic whereas that of Obsidian is Glassy. Rapakivi Granite appears Veined or Pebbled and Obsidian appears Shiny. The luster of Rapakivi Granite is dull to grainy with sporadic parts pearly and vitreous while that of Obsidian is vitreous. Rapakivi Granite is available in black, grey, orange, pink, white colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Rapakivi Granite are cemetery markers, commemorative tablets, creating artwork, curling, laboratory bench tops, tombstones and that of Obsidian are creating artwork, mirror, used in aquariums.