Andesite

Porphyry

Andesite and Porphyry

Andesite

Porphyry

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Definition

Andesite is a dark, fine-grained, brown or greyish intermediate volcanic rock which is a commonly found in lava

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

History

Origin

North America

Egypt

Discoverer

Theodor von Gümbel

Unknown

Etymology

From Andes mountains, where it is found in abundance

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Porphyritic

Color

Bluish - Grey, Grey, Pink, Yellow

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration, Kitchens

Decorative Aggregates, Interior Decoration

Exterior Uses

Office Buildings, Roof Tiles

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Cobblestones, Construction Aggregate, for Road Aggregate

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture, Small Figurines

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Commemorative Tablets, Creating Artwork

Creating Artwork, Gemstone, Jewelry

Types

Icelandite

Rhomb Porphyry

Features

Generally rough to touch, High silica content, Is one of the oldest rock

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

Archaeological Significance

Monuments

Famous Monuments

Middle of the Earth in Ecuador

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Andesite is a fine-grained igneous rock that forms when the magma is erupted onto the surface and is crystallized quickly.

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.

Composition

Mineral Content

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite, Magnetite, Plagioclase, Pyroxene, Zircon

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

Compound Content

Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

76-7

1 7

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Grain Size

Very fine-grained

Fine Grained

Fracture

Uneven

Irregular

Streak

White

Porosity

Less Porous

Luster

Vitreous

Dull

Compressive Strength

225.00 N/mm²150.00 N/mm²

0.15 450

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Cleavage

Toughness

1.1

1.7

Specific Gravity

2.5-2.82.5-4

0 8.4

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Transparency

Opaque

Translucent to Opaque

Density

2.11-2.36 g/cm³2.5-2.52 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

2.39 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Indonesia, Japan, Nepal, South Korea

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

Africa

Egypt, Ethiopia, Morocco, Namibia, South Africa, Tanzania

Egypt, Ethiopia, Ghana, South Africa

Europe

Austria, Finland, Germany, Italy, Romania, Turkey, United Kingdom

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

Others

Greenland

Deposits in Western Continents

North America

Mexico, USA

Canada, Cuba, Jamaica, USA

South America

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

All about Andesite and Porphyry Properties

Know all about Andesite and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Andesite and Porphyry belong to Igneous Rocks.Texture of Andesite is Aphanitic to Porphyritic whereas that of Porphyry is Porphyritic. Andesite appears Dull and Soft and Porphyry appears Dull. The luster of Andesite is vitreous while that of Porphyry is dull. Andesite is available in bluish - grey, grey, pink, yellow colors whereas Porphyry is available in black, brown, green, grey, red, rust, white colors. The commercial uses of Andesite are commemorative tablets, creating artwork and that of Porphyry are creating artwork, gemstone, jewelry.