Scoria

Porphyry

Scoria and Porphyry

Scoria

Porphyry

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Definition

Scoria is a dark-colored extrusive igneous rock with abundant round bubble-like cavities

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

History

Origin

Egypt

Discoverer

Unknown

Etymology

From late Middle English (denoting slag from molten metal), from Greek skōria refuse, from skōr dung

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

Class

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Vesicular

Porphyritic

Color

Black, Brown, Dark Grey to Black, Red

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Glassy and Vesicular

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Interior Decoration

Exterior Uses

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Cement Manufacture, Construction Aggregate, for Road Aggregate, In landscaping and drainage works

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

As a traction material on snow-covered roads, Creating Artwork, High-temperature insulation, In gas barbecue grills

Creating Artwork, Gemstone, Jewelry

Types

Basaltic Scoria and Andesitic Scoria

Rhomb Porphyry

Features

Available in Lots of Colors and Patterns, Generally rough to touch, Surfaces are often shiny

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

Scoria forms when magma containing huge amount of dissolved gas flows from a volcano during an eruption.

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

Apatite, Biotite, Calcite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz, Silica

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

Compound Content

Ca, NaCl

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact 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

Properties

Physical Properties

Hardness

5-66-7

1 7

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Grain Size

Fine Grained

Fracture

Conchoidal

Irregular

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Subvitreous to Dull

Dull

Compressive Strength

70.00 N/mm²150.00 N/mm²

0.15 450

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Cleavage

Perfect

Toughness

2.1

1.7

Specific Gravity

-99992.5-4

0 8.4

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Transparency

Opaque

Translucent to Opaque

Density

-9999 g/cm³2.5-2.52 g/cm³

0 1400

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Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

Afghanistan, Indonesia, Japan, Russia

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

Africa

Ethiopia, Kenya, Tanzania

Egypt, Ethiopia, Ghana, South Africa

Europe

Greece, Hungary, Iceland, Italy, Turkey

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

Others

Greenland

Deposits in Western Continents

North America

Bahamas, Barbados, Canada, Costa Rica, Cuba, Jamaica, Mexico, USA

Canada, Cuba, Jamaica, USA

South America

Argentina, Chile, Ecuador, Peru

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New Zealand, Western Australia

New South Wales, New Zealand, Western Australia

All about Scoria and Porphyry Properties

Know all about Scoria and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Scoria and Porphyry belong to Igneous Rocks.Texture of Scoria is Vesicular whereas that of Porphyry is Porphyritic. Scoria appears Glassy and Vesicular and Porphyry appears Dull. The luster of Scoria is subvitreous to dull while that of Porphyry is dull. Scoria is available in black, brown, dark grey to black, red colors whereas Porphyry is available in black, brown, green, grey, red, rust, white colors. The commercial uses of Scoria are as a traction material on snow-covered roads, creating artwork, high-temperature insulation, in gas barbecue grills and that of Porphyry are creating artwork, gemstone, jewelry.