Shale

Porphyry

Shale and Porphyry

Shale

Porphyry

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Definition

Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles

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

Johann Gottlob Lehmann

Unknown

Etymology

From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,

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

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Fine Grained Rock, Opaque Rock

Texture

Clastic, Splintery

Porphyritic

Color

Black, Brown, Buff, Green, Grey, Red, Yellow

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Muddy

Dull

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Office Buildings

Garden Decoration, Paving Stone

Other Architectural Uses

Curbing

Industry

Construction Industry

Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar

Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Creating Artwork, Pottery

Creating Artwork, Gemstone, Jewelry

Types

Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale

Rhomb Porphyry

Features

Easily splits into thin plates, Generally rough to touch, Very fine grained rock

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

Archaeological Significance

Monuments

Famous Monuments

Jantar Mantar in India

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Present

Absent

Formation

Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.

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

Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides

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

Compound Content

Ca, Fe, Mg, Silicon Dioxide, Sodium

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, 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

36-7

1 7

👆🏻

Grain Size

Very fine-grained

Fine Grained

Fracture

Irregular

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Dull

Compressive Strength

95.00 N/mm²150.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

2.6

1.7

Specific Gravity

2.2-2.82.5-4

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

2.4-2.8 g/cm³2.5-2.52 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.39 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, China, India, Russia

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

Africa

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Egypt, Ethiopia, Ghana, South Africa

Europe

Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland

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, Chile, Colombia, Ecuador, Peru, Venezuela

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Victoria, Western Australia

New South Wales, New Zealand, Western Australia

All about Shale and Porphyry Properties

Know all about Shale and Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Shale belongs to Sedimentary Rocks while Porphyry belongs to Igneous Rocks.Texture of Shale is Clastic, Splintery whereas that of Porphyry is Porphyritic. Shale appears Muddy and Porphyry appears Dull. The luster of Shale and Porphyry is dull. Shale is available in black, brown, buff, green, grey, red, yellow colors whereas Porphyry is available in black, brown, green, grey, red, rust, white colors. The commercial uses of Shale are creating artwork, pottery and that of Porphyry are creating artwork, gemstone, jewelry.