Porphyry

Icelandite

Porphyry and Icelandite

Porphyry

Icelandite

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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

Icelandite belongs to volcanic igneous rocks which is rich in iron and belongs to andesite rock

History

Origin

Egypt

Iceland

Discoverer

Unknown

Ian S. E. Carmichael

Etymology

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

From its origin place near Cenozoic volcano near the parsonage Þingmúli in East Iceland

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Porphyritic

Aphanitic to Porphyritic

Color

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

Bluish - Grey, Grey, Pink, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Dull and Soft

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

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

Exterior Uses

Garden Decoration, Paving Stone

Office Buildings, Roof Tiles

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

Cobblestones, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Jewellery, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Cemetery Markers, Creating Artwork

Types

Rhomb Porphyry

Intermediate volcanic rock

Features

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

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

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.

Icelandite 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.

Composition

Mineral Content

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

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

Compound Content

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

Silicon 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

Biological Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

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

Properties

Physical Properties

Hardness

6-77

1 7

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Grain Size

Fine Grained

Very fine-grained

Fracture

Irregular

Uneven

Streak

White

Porosity

Less Porous

Luster

Dull

Vitreous

Compressive Strength

150.00 N/mm²200.00 N/mm²

0.15 450

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Cleavage

Toughness

1.7

1.1

Specific Gravity

2.5-42.5-2.8

0 8.4

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Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³2.11-2.36 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K2.39 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

India, Indonesia, Japan, Nepal, South Korea

Africa

Egypt, Ethiopia, Ghana, South Africa

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

Europe

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

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

Others

Greenland

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

Mexico, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

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

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

All about Porphyry and Icelandite Properties

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