Porphyry

Trachyte

Porphyry and Trachyte

Porphyry

Trachyte

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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

Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar

History

Origin

Egypt

Discoverer

Unknown

Alexandre Brongniart and René Just Haüy

Etymology

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

From Greek trakhus rough’ or trakhutēs roughness

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Plutonic

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Porphyritic

Aphanitic to Porphyritic

Color

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

Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White

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

Decorative Aggregates, Flooring, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

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

Other Architectural Uses

Curbing

Industry

Construction Industry

Construction Aggregate

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Creating Artwork, Gemstone, Jewelry

Cemetery Markers, Creating Artwork

Types

Rhomb Porphyry

Felsic volcanic 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.

Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.

Composition

Mineral Content

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

Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz

Compound Content

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

Potassium Oxide, Sodium Oxide, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Cataclastic Metamorphism, Contact 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

1 7

👆🏻

Grain Size

Fine Grained

Fracture

Irregular

Streak

White

Porosity

Less Porous

Luster

Dull

Metallic

Compressive Strength

150.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.7

Specific Gravity

2.5-42.7

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.5-2.52 g/cm³2.43-2.45 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.71 kJ/Kg K0.84 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 Trachyte Properties

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