Porphyry

Shonkinite

Porphyry and Shonkinite

Porphyry

Shonkinite

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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

Shonkinite is a rare, dark-coloured and intrusive igneous rock which contains augite and orthoclase feldspar as its primary constituents

History

Origin

Egypt

USA

Discoverer

Unknown

Etymology

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

From the name of Shonkin Sag ranges in the Highwood Mountains of north-central Montana, US

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, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Porphyritic

Earthy

Color

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

Brown, Buff, Cream, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Banded and Foilated

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Flooring, Homes, 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, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Cemetery Markers, Creating Artwork

Types

Rhomb Porphyry

Igneous rock

Features

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

Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable

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.

Shonkinites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

Composition

Mineral Content

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

Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz

Compound Content

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

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, 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, Sea Erosion, Water Erosion

Properties

Physical Properties

Hardness

6-75.5-6

1 7

👆🏻

Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Irregular

Streak

White

Porosity

Less Porous

Luster

Dull

Subvitreous to Dull

Compressive Strength

150.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.7

Specific Gravity

2.5-42.6-2.7

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³2.6-2.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam

Africa

Egypt, Ethiopia, Ghana, South Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

Europe

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

Bulgaria, England, Germany, Norway, Romania, Switzerland

Others

Greenland

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Brazil, Chile

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

New Zealand, Queensland, South Australia, Western Australia

All about Porphyry and Shonkinite Properties

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