Tephrite

Porphyry

Tephrite and Porphyry

Tephrite

Porphyry

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Definition

Tephrite is an aphanitic to porphyritic textured, volcanic igneous rock

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

History

Origin

Germany

Egypt

Discoverer

Van Tooren

Unknown

Etymology

From Greek tephra, ashes from Indo-European base, to burn

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

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

Fine Grained Rock, Opaque Rock

Texture

Aphanitic to Porphyritic

Porphyritic

Color

Black, Brown, Green, Grey, White

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Vesicular

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Flooring, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

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

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Landscaping

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Production of Lime, Soil Conditioner

Creating Artwork, Gemstone, Jewelry

Types

Igneous rock

Rhomb Porphyry

Features

Host Rock for Lead

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

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Tephrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

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.

Composition

Mineral Content

Alkali feldspar, Nepheline, Plagioclase, Pyroxene

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

Compound Content

CaO, Carbon Dioxide, MgO, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

6.56-7

1 7

👆🏻

Grain Size

Medium to Fine Coarse Grained

Fine Grained

Fracture

Uneven

Irregular

Streak

Bluish Black

White

Porosity

Very Less Porous

Less Porous

Luster

Subvitreous to Dull

Dull

Compressive Strength

90.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Crenulation and Pervasive

Toughness

2.4

1.7

Specific Gravity

2.862.5-4

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

2.8-2.9 g/cm³2.5-2.52 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.92 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Africa

Namibia, Uganda

Egypt, Ethiopia, Ghana, South Africa

Europe

Germany, Hungary, Italy, Portugal, Spain

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

Others

Greenland

Deposits in Western Continents

North America

USA

Canada, Cuba, Jamaica, USA

South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New South Wales, New Zealand, Western Australia

All about Tephrite and Porphyry Properties

Know all about Tephrite and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Tephrite and Porphyry belong to Igneous Rocks.Texture of Tephrite is Aphanitic to Porphyritic whereas that of Porphyry is Porphyritic. Tephrite appears Vesicular and Porphyry appears Dull. The luster of Tephrite is subvitreous to dull while that of Porphyry is dull. Tephrite is available in black, brown, green, grey, white colors whereas Porphyry is available in black, brown, green, grey, red, rust, white colors. The commercial uses of Tephrite are production of lime, soil conditioner and that of Porphyry are creating artwork, gemstone, jewelry.