Porphyry and Ignimbrite

Porphyry

Ignimbrite

Definition

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

Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows

History

Origin

Egypt

New Zealand

Discoverer

Unknown

Patrick Marshall

Etymology

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

From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Porphyritic

Aphanitic

Color

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

Beige, Black, Brown, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

Yes

Scratch Resistant

Yes

Stain Resistant

Yes

Wind Resistant

Yes

Acid Resistant

Yes

Appearance

Dull

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, Garden Decoration, Office Buildings, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

Building houses or walls, Construction Aggregate

Medical Industry

Not Yet Used

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Cemetery Markers, Commemorative Tablets, Creating Artwork

Types

Rhomb Porphyry

Not Available

Features

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

Always found as volcanic pipes over deep continental crust

Archaeological Significance

Monuments

Used

Famous Monuments

Data Not Available

Sculpture

Used

Famous Sculptures

Data Not Available

Pictographs

Not Used

Used

Petroglyphs

Not Used

Used

Figurines

Used

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.

Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.

Composition

Mineral Content

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

Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz

Compound Content

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

Ca, NaCl

Transformation

Metamorphism

Yes

Types of Metamorphism

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

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

Weathering

Yes

Types of Weathering

Biological Weathering, Chemical Weathering, Not Registered

Biological Weathering, Chemical Weathering

Erosion

Yes

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion

Properties

Physical Properties

Hardness

6-7

4-6

Grain Size

Fine Grained

Fracture

Irregular

Uneven

Streak

White

Porosity

Less Porous

Highly Porous

Luster

Dull

Vitreous to Dull

Compressive Strength

Not Available

243.80 N/mm²

Cleavage

Imperfect

Not Available

Toughness

1.7

Not Available

Specific Gravity

2.5-4

2.73

Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³

1-1.8 g/cm³

Thermal Properties

Specific Heat Capacity

Not Available

0.20 kJ/Kg K

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen

Africa

Egypt, Ethiopia, Ghana, South Africa

Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda

Europe

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

France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom

Others

Greenland

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

Canada, Costa Rica, Panama, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

Central Australia, Western Australia

Summary >>

<< Reserves

All about Porphyry and Ignimbrite Properties

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