Shale

Dacite

Shale and Dacite

Shale

Dacite

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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

Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite

History

Origin

Romania and Moldova, Europe

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 Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described

Class

Sedimentary Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Opaque Rock

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Clastic, Splintery

Aphanitic to Porphyritic

Color

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

Bluish - Grey, Brown, Grey, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Muddy

Vesicular

Uses

Architecture

Interior Uses

Decorative Aggregates, Homes, Interior Decoration

Decorative Aggregates, Entryways, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Office Buildings

As Building Stone, Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

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

As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping

Medical Industry

Antiquity Uses

Artifacts, Sculpture

Artifacts

Other Uses

Commercial Uses

Creating Artwork, Pottery

Commemorative Tablets, Creating Artwork

Types

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

Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite

Features

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

Host Rock for Lead, Is one of the oldest rock

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.

Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.

Composition

Mineral Content

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

Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon

Compound Content

Ca, Fe, Mg, Silicon Dioxide, Sodium

Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Chemical Erosion

Properties

Physical Properties

Hardness

32-2.25

1 7

👆🏻

Grain Size

Very fine-grained

Medium to Fine Coarse Grained

Fracture

Conchoidal

Streak

White

Porosity

Highly Porous

Less Porous

Luster

Dull

Subvitreous to Dull

Compressive Strength

95.00 N/mm²70.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Perfect

Toughness

2.6

Specific Gravity

2.2-2.82.86-2.87

0 8.4

👆🏻

Transparency

Opaque

Translucent

Density

2.4-2.8 g/cm³2.77-2.771 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.39 kJ/Kg K0.92 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

Bangladesh, China, India, Russia

Africa

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Europe

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

France, Greece, Romania, Scotland, Spain

Others

Deposits in Western Continents

North America

USA

South America

Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

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

New Zealand, South Australia, Western Australia

All about Shale and Dacite Properties

Know all about Shale and Dacite properties here. All properties of rocks are important as they define the type of rock and its application. Shale belongs to Sedimentary Rocks while Dacite belongs to Igneous Rocks.Texture of Shale is Clastic, Splintery whereas that of Dacite is Aphanitic to Porphyritic. Shale appears Muddy and Dacite appears Vesicular. The luster of Shale is dull while that of Dacite is subvitreous to dull. Shale is available in black, brown, buff, green, grey, red, yellow colors whereas Dacite is available in bluish - grey, brown, grey, light to dark grey colors. The commercial uses of Shale are creating artwork, pottery and that of Dacite are commemorative tablets, creating artwork.