Porphyry

Skarn

Porphyry and Skarn

Porphyry

Skarn

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1 Definition

1.1 Definition

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

Skarns are formed during regional or contact metamorphism and from a variety of metasomatic processes involving fluids of magmatic, metamorphic, and/or marine origin

1.2 History

1.2.1 Origin

Egypt

USA, Australia

1.2.2 Discoverer

Unknown

Tornebohm

1.3 Etymology

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

From an old Swedish mining term originally used to describe a type of silicate gangue or waste rock.

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Plutonic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Porphyritic

Earthy, Mud-rich, Rough

2.2 Color

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

Black, Brown, Colourless, Green, Grey, White

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Paving Stone

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 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, Gold and Silver production, Manufacture of Magnesium and Dolomite Refractories

3.2.2 Medical Industry

Not Yet Used

Not Applicable

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone, Jewelry

Creating Artwork, Gemstone, Jewelry, Metallurgical Flux, Source of Magnesia (MgO)

4 Types

4.1 Types

Rhomb Porphyry

Endoskarns

4.2 Features

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

Host Rock for Lead, Zinc and Copper Deposits

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Used

4.4 Fossils

Absent

5 Formation

5.1 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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Skarn is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

5.2 Composition

5.2.1 Mineral Content

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

Calcite, Enstatite, Epidote, Garnet, Magnetite, Pyroxene, Titanite

5.2.2 Compound Content

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

Au, CaO, Carbon Dioxide, Cu, Fe, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

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

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Not Registered

Not Applicable

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Not Applicable

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-76.5

1 7

6.1.2 Grain Size

Fine Grained

6.1.3 Fracture

Irregular

6.1.4 Streak

White

Light to dark brown

6.1.5 Porosity

Less Porous

6.1.6 Luster

Dull

Waxy and Dull

6.1.7 Compressive Strength

NANA

0.15 450

6.1.8 Cleavage

Imperfect

Slaty

6.1.9 Toughness

1.7

2.4

6.1.10 Specific Gravity

2.5-42.86

0 8.4

6.1.11 Transparency

Translucent to Opaque

Opaque

6.1.12 Density

2.5-2.52 g/cm³2.8-2.9 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.92 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

China, India, Russia, Saudi Arabia, South Korea, Sri Lanka

7.1.2 Africa

Egypt, Ethiopia, Ghana, South Africa

South Africa, Western Africa

7.1.3 Europe

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

United Kingdom

7.1.4 Others

Greenland

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Cuba, Jamaica, USA

Canada

7.2.2 South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Brazil, Colombia, Paraguay

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand, Western Australia

Central Australia, Western Australia

All about Porphyry and Skarn Properties

Know all about Porphyry and Skarn properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry belongs to Igneous Rocks while Skarn belongs to Metamorphic Rocks.Texture of Porphyry is Porphyritic whereas that of Skarn is Earthy, Mud-rich, Rough. Porphyry appears Dull and Skarn appears Dull. The luster of Porphyry is dull while that of Skarn is waxy and dull. Porphyry and Skarn are available in black, brown, colourless, green, grey, red, rust, white colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Skarn are creating artwork, gemstone, jewelry, metallurgical flux, source of magnesia (mgo).