Definition
Granite is a very hard, granular, crystalline igneous rock which consists mainly of quartz, mica, and feldspar and is often used as building stone
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
Discoverer
Alexander von Humboldt
Obsius
Etymology
From Italian granito, which means grained rock, from grano grain, and from Latin granum
From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Opaque Rock
Texture
Granular, Phaneritic
Glassy
Color
Black, Grey, Orange, Pink, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined or Pebbled
Shiny
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Bridges, Paving Stone, Garden Decoration, Near Swimming Pools, Office Buildings, Resorts
Garden Decoration
Other Architectural Uses
Curbing
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Construction Industry
As Dimension Stone
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Monuments, Sculpture, Small Figurines
Artifacts, Jewellery
Commercial Uses
Curling, Gemstone, Laboratory bench tops, Tombstones, Used in aquariums
Creating Artwork, Mirror, Used in aquariums
Types
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite, Hybrid Granite, Granodiorite and Alkali Feldspar Granite
Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian
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
Archaeological Significance
Famous Monuments
Agia Sophia in Istanbul, Turkey, Blue Domed Church in Santorini, Greece, Blue Mosque in Istanbul, Charminar in Hyderabad, India, Diana, Princess of Wales Memorial Fountain in London, UK, Ephesus in Turkey, Georgia Guidestones in Georgia, US, Hermitage in Saint Petersburg, Khajuraho Temples, India, Mahabalipuram in Tamil Nadu, India, Mysore Palace in Karnataka, India, Signers Monument in Augusta, Georgia, Statue of Liberty in New York, USA, Taj Mahal in Agra, India, Tower Bridge in London, Vietnam Veterans Memorial in Washington, US, Washington Monument, US
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Famous Sculptures
Avukana Buddha Statue in Sri Lanka, Lincoln Memorial in America, Mount Rushmore National Memorial in South Dakota, US, The Colossal Red Granite Statue of Amenhotep III in Karnak, Egypt
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Formation
Granite is an intrusive 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.
Mineral Content
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
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Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Large and Coarse Grained
-
Porosity
Less Porous
Very Less Porous
Luster
Dull to Grainy with Sporadic parts Pearly and Vitreous
Vitreous
Specific Gravity
2.6-2.7
2.6-2.7
Transparency
Opaque
Translucent
Density
2.65-2.75 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Afghanistan, Indonesia, Japan, Russia
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Kenya
Europe
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic
Greece, Hungary, Iceland, Italy, Turkey
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
-
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent