Porphyry

Diabase

Porphyry and Diabase

Porphyry

Diabase

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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

Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar

History

Origin

Egypt

Germany

Discoverer

Unknown

Christian Leopold von Buch

Etymology

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

From Greek di + base

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Porphyritic

Aphanitic, Granular

Color

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

Dark Grey to Black

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens

Exterior Uses

Garden Decoration, Paving Stone

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones

Types

Rhomb Porphyry

Dolerite

Features

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

Smooth to touch

Archaeological Significance

Monuments

Famous Monuments

Stonehenge in English county of Wiltshire

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.

Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.

Composition

Mineral Content

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

Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine

Compound Content

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

Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Properties

Physical Properties

Hardness

6-77

1 7

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Grain Size

Fine Grained

Fine to Medium Grained

Fracture

Irregular

Conchoidal

Streak

White

Black

Porosity

Less Porous

Highly Porous

Luster

Dull

Compressive Strength

150.00 N/mm²225.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.7

1.6

Specific Gravity

2.5-42.86-2.87

0 8.4

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Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³2.7-3.3 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.84 kJ/Kg K

0.14 3.2

👆🏻

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

India

Africa

Egypt, Ethiopia, Ghana, South Africa

South Africa, Tanzania

Europe

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

Germany, Greece, Italy, Scotland, Turkey

Others

Greenland

Antarctica, Greenland

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

Canada, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Argentina, Brazil, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

Central Australia, New Zealand, Queensland, Western Australia

All about Porphyry and Diabase Properties

Know all about Porphyry and Diabase properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry and Diabase belong to Igneous Rocks.Texture of Porphyry is Porphyritic whereas that of Diabase is Aphanitic, Granular. Porphyry appears Dull and Diabase appears Vesicular. The luster of Porphyry is dull while that of Diabase is . Porphyry is available in black, brown, green, grey, red, rust, white colors whereas Diabase is available in dark grey to black colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Diabase are an oil and gas reservoir, cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.