Porphyry

Granite

Porphyry and Granite

Porphyry

Granite

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Definition

Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix

Granite is a very hard, granular, crystalline igneous rock which consists mainly of quartz, mica, and feldspar and is often used as building stone

History

Origin

Egypt

Discoverer

Unknown

Alexander von Humboldt

Etymology

From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites

From Italian granito, which means grained rock, from grano grain, and from Latin granum

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Porphyritic

Granular, Phaneritic

Color

Black, Brown, Green, Grey, Red, Rust, White

Black, Grey, Orange, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

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Scratch Resistant

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Stain Resistant

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Wind Resistant

✔ ✘

Acid Resistant

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Appearance

Dull

Veined or Pebbled

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

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

Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, As Facing Stone, Bridges, Paving Stone, Garden Decoration, Near Swimming Pools, Office Buildings, Resorts

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

As Dimension Stone

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Curling, Gemstone, Laboratory bench tops, Tombstones, Used in aquariums

Types

Rhomb Porphyry

Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite, Hybrid Granite, Granodiorite and Alkali Feldspar Granite

Features

Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny

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

Archaeological Significance

Monuments

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

Sculpture

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

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

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

Composition

Mineral Content

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

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

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

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

Transformation

Metamorphism

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Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Sea Erosion, Water Erosion

Properties

Physical Properties

Hardness

6-76-7

1 7

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Grain Size

Fine Grained

Large and Coarse Grained

Fracture

Irregular

Streak

White

Porosity

Less Porous

Luster

Dull

Dull to Grainy with Sporadic parts Pearly and Vitreous

Compressive Strength

150.00 N/mm²175.00 N/mm²

0.15 450

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Cleavage

Toughness

1.7

Specific Gravity

2.5-42.6-2.7

0 8.4

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Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³2.65-2.75 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.79 kJ/Kg K

0.14 3.2

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Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam

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

Africa

Egypt, Ethiopia, Ghana, South Africa

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

Europe

Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland

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

Others

Greenland

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

Canada, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

All about Porphyry and Granite Properties

Know all about Porphyry and Granite properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry and Granite belong to Igneous Rocks.Texture of Porphyry is Porphyritic whereas that of Granite is Granular, Phaneritic. Porphyry appears Dull and Granite appears Veined or Pebbled. The luster of Porphyry is dull while that of Granite is dull to grainy with sporadic parts pearly and vitreous. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas Granite is available in black, grey, orange, pink, white colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Granite are curling, gemstone, laboratory bench tops, tombstones, used in aquariums.