Porphyry

Schist

Porphyry and Schist

Porphyry

Schist

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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

Schist is a medium grade metamorphic rock with medium to large, flat, sheet like grains in a preferred orientation

1.2 History

1.2.1 Origin

Egypt

Unknown

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From French schiste, Greek skhistos i.e. split

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Plutonic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Porphyritic

Foliated, Platy

2.2 Color

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

Black, Blue, Brown, Dark Brown, Green, Grey, Silver

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

81% Metamorphic Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

42% Metamorphic Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

19% Metamorphic Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

15% Metamorphic Rocks Rocks have it !

2.5 Appearance

Dull

Layered and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Paving Stone

3.1.3 Other Architectural Uses

Curbing

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

Construction Aggregate

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

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone, Jewelry

Used in aquariums, Writing Slates

4 Types

4.1 Types

Rhomb Porphyry

Mica Schists, Calc-Silicate Schists, Graphite Schists, Blueschists, Whiteschists, Greenschists, Hornblende Schist, Talc Schist, Chlorite Schist, Garnet Schist, Glaucophane schist.

4.2 Features

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

Easily splits into thin plates, Smooth to touch

4.3 Archaeological Significance

4.3.1 Monuments

Used

Not Yet Used

4.3.2 Famous Monuments

Data Not Available

Not Applicable

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

Not Yet 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.

Schist formed by dynamic metamorphism at high temperatures and pressures that aligns the grains of mica, hornblende and other elongated minerals into thin layers.

5.2 Composition

5.2.1 Mineral Content

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

Alusite, Amphibole, Biotite, Chlorite, Epidote, Feldspar, Garnet, Graphite, Hornblade, Kyanite, Micas, Muscovite or Illite, Porphyroblasts, Quartz, Sillimanite, Staurolite, Talc

5.2.2 Compound Content

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

CaO, Carbon Dioxide, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

50% Metamorphic Rocks Rocks have it !

5.3.2 Types of Metamorphism

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

Not Applicable

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Not Registered

Biological Weathering, Chemical Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

77% Metamorphic Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-7

3.5-4

6.1.2 Grain Size

Fine Grained

Medium to Fine Coarse Grained

6.1.3 Fracture

Irregular

Conchoidal

6.1.4 Streak

White

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Dull

Shiny

6.1.7 Compressive Strength

What Is Flint

⊕

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▼

Not Available

Rank: N/A (Overall)▶

Not Available

Rank: N/A (Overall)▶

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What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

1.3.2 Cleavage

Imperfect

Slaty

1.3.3 Toughness

1.7

1.5

1.3.4 Specific Gravity

2.5-4

2.5-2.9

1.3.5 Transparency

Translucent to Opaque

Opaque

1.3.6 Density

2.5-2.52 g/cm³

2.8-2.9 g/cm³

1.4 Thermal Properties

1.4.1 Specific Heat Capacity

What Is Banded ..

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▶

▼

Not Available

Rank: N/A (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

1.4.2 Resistance

Heat Resistant, Impact Resistant

Impact Resistant, Pressure Resistant, Water Resistant

2 Reserves

2.1 Deposits in Eastern Continents

2.1.1 Asia

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

Afghanistan, Bangladesh, Bhutan, China, India, Japan, Kazakhstan, Malaysia, Pakistan, Russia, Thailand, Turkey, Vietnam

2.1.2 Africa

Egypt, Ethiopia, Ghana, South Africa

Egypt, Ethiopia, Morocco, Nigeria, South Africa

2.1.3 Europe

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

Austria, England, France, Georgia, Germany, Italy, Liechtenstein, Monaco, Norway, Slovenia, Spain, Sweden, Switzerland

2.1.4 Others

Greenland

Not Yet Found

2.2 Deposits in Western Continents

2.2.1 North America

Canada, Cuba, Jamaica, USA

Canada, Costa Rica, Cuba, Mexico, Panama, USA

2.2.2 South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Brazil, Colombia, Guyana

2.3 Deposits in Oceania Continent

2.3.1 Australia

New South Wales, New Zealand, Western Australia

New South Wales, New Zealand, Queensland

All about Porphyry and Schist Properties

Know all about Porphyry and Schist properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry belongs to Igneous Rocks while Schist belongs to Metamorphic Rocks.Texture of Porphyry is Porphyritic whereas that of Schist is Foliated, Platy. Porphyry appears Dull and Schist appears Layered and Shiny. The luster of Porphyry is dull while that of Schist is shiny. Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors whereas Schist is available in black, blue, brown, dark brown, green, grey, silver colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Schist are used in aquariums, writing slates.