Porphyry

Metapelite

Porphyry and Metapelite

Porphyry

Metapelite

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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

Metapelite is an old and currently not widely used field geological term for a clay rich fine-grained clastic sediment or sedimentary rock, i.e. mud or a mudstone

History

Origin

Egypt

Discoverer

Unknown

Etymology

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

From Pelos or clay in Greek

Class

Igneous Rocks

Metamorphic 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

Foliated

Color

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

Dark Greenish - Grey, Green, Light Green, Light Greenish Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull

Banded

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

As Building Stone, As Facing Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

Cement Manufacture, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Commemorative Tablets, Creating Artwork

Types

Rhomb Porphyry

Metamorphic rock

Features

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

Easily splits into thin plates, It is One of the Oldest, Strongest and Hardest Rock

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.

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

Composition

Mineral Content

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

Albite, Chlorite, Quartz

Compound Content

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

Aluminium Oxide, CaO, MgO

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, Water Erosion, Wind Erosion

Properties

Physical Properties

Hardness

6-75-6

1 7

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Grain Size

Fine Grained

Medium to Fine Coarse Grained

Fracture

Irregular

Fibrous

Streak

White

Porosity

Less Porous

Highly Porous

Luster

Dull

Earthy

Compressive Strength

150.00 N/mm²40.00 N/mm²

0.15 450

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Cleavage

Toughness

1.7

Specific Gravity

2.5-43.4-3.7

0 8.4

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Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³0-300 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.72 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Africa

Egypt, Ethiopia, Ghana, South Africa

Western Africa

Europe

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

United Kingdom

Others

Greenland

Deposits in Western Continents

North America

Canada, Cuba, Jamaica, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Brazil, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Western Australia

Central Australia, Western Australia

All about Porphyry and Metapelite Properties

Know all about Porphyry and Metapelite properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry belongs to Igneous Rocks while Metapelite belongs to Metamorphic Rocks.Texture of Porphyry is Porphyritic whereas that of Metapelite is Foliated. Porphyry appears Dull and Metapelite appears Banded. The luster of Porphyry is dull while that of Metapelite is earthy. Porphyry is available in black, brown, green, grey, red, rust, white colors whereas Metapelite is available in dark greenish - grey, green, light green, light greenish grey colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Metapelite are commemorative tablets, creating artwork.