Porphyry

Dunite

Porphyry and Dunite

Porphyry

Dunite

Add ⊕

Definition

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

Dunite is a green to brownish coarse-grained igneous rock mainly consisting of olivine

History

Origin

Egypt

New Zealand

Discoverer

Unknown

Ferdinand von Hochstetter

Etymology

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

From the name of Dun Mountain, New Zealand, + -ite1

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Porphyritic

Phaneritic

Color

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

Dark Greenish - Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Rough and Shiny

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds

Types

Rhomb Porphyry

Dunite

Features

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

Constitutes upper part of the Earth's mantle, Generally rough to touch, Host rock for Diamond, 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.

Dunite is a plutonic ultramafic igneous rock consisting almost m olivine. It can be formed in two ways.

Composition

Mineral Content

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

Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene

Compound Content

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

Ca, CaO, Fe, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Coastal Erosion, Glacier Erosion, Water Erosion

Properties

Physical Properties

Hardness

6-73.5-4

1 7

👆🏻

Grain Size

Fine Grained

Coarse Grained

Fracture

Irregular

Streak

White

Porosity

Less Porous

Luster

Dull

Shiny

Compressive Strength

150.00 N/mm²107.55 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.7

2.1

Specific Gravity

2.5-43-3.01

0 8.4

👆🏻

Transparency

Translucent to Opaque

Density

2.5-2.52 g/cm³2.84-2.85 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K1.25 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Indonesia, Kazakhstan, Russia, South Korea, Thailand, Turkey

Africa

Egypt, Ethiopia, Ghana, South Africa

Morocco, South Africa

Europe

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

Finland, France, Georgia, Germany, Great Britain, Italy, Kazakhstan, Netherlands, Norway, Spain, Switzerland

Others

Greenland

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

Canada, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Argentina, Brazil, Colombia, Ecuador, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

New Zealand, Western Australia

All about Porphyry and Dunite Properties

Know all about Porphyry and Dunite properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry and Dunite belong to Igneous Rocks.Texture of Porphyry is Porphyritic whereas that of Dunite is Phaneritic. Porphyry appears Dull and Dunite appears Rough and Shiny. The luster of Porphyry is dull while that of Dunite is shiny. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas Dunite is available in dark greenish - grey colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Dunite are creating artwork, gemstone, jewelry, source of chromite, platinum, nickel and garnet, source of diamonds.