Porphyry

Kimberlite

Porphyry and Kimberlite

Porphyry

Kimberlite

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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

Kimberlite is a rare, blue-tinged, coarse-grained intrusive igneous rock, which sometimes contains diamonds and is mostly found in South Africa and Siberia.

History

Origin

Egypt

Kimberley, South Africa

Discoverer

Unknown

John W. Judd

Etymology

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

From Kimberley +‎ -ite, from the name of the South African town of Kimberley where the rock was first found.

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Opaque Rock

Texture

Porphyritic

Color

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

Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Dull and Banded

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Taken as a Supplement for Calcium or Magnesium

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)

Types

Rhomb Porphyry

Basaltic Kimberlites and Micaceous Kimberlites

Features

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

Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny

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.

Kimberlite is an igneous rock and is the main source of diamonds. Its formation takes place deep beneath the Earth’s surface between 150 to 450 kilometres, and are erupted rapidly and violently.

Composition

Mineral Content

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

Garnet, Olivine, Phlogopite, Pyroxene

Compound Content

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

Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, 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

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

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

Properties

Physical Properties

Hardness

6-76-7

1 7

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Grain Size

Fine Grained

Fine to Coarse Grained

Fracture

Irregular

Conchoidal

Streak

White

Porosity

Less Porous

Very Less Porous

Luster

Dull

Subvitreous to Dull

Compressive Strength

150.00 N/mm²260.00 N/mm²

0.15 450

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Cleavage

Conchoidal

Toughness

1.7

Specific Gravity

2.5-42.86-2.87

0 8.4

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Transparency

Translucent to Opaque

Density

2.5-2.52 g/cm³2.95-2.96 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Russia

Africa

Egypt, Ethiopia, Ghana, South Africa

Angola, Botswana, Cameroon, Ethiopia, South Africa

Europe

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

England, Hungary, Iceland, United Kingdom

Others

Greenland

Antarctica

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

Canada, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Argentina, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

New South Wales, New Zealand, South Australia, Western Australia

All about Porphyry and Kimberlite Properties

Know all about Porphyry and Kimberlite properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry and Kimberlite belong to Igneous Rocks.Texture of Porphyry is Porphyritic whereas that of Kimberlite is Porphyritic. Porphyry appears Dull and Kimberlite appears Dull and Banded. The luster of Porphyry is dull while that of Kimberlite is subvitreous to dull. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas Kimberlite is available in black, bluish - grey, brown, dark greenish - grey, green, grey colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Kimberlite are an oil and gas reservoir, as a feed additive for livestock, gemstone, metallurgical flux, production of lime, soil conditioner, source of magnesia (mgo).