Blueschist

Shale

Blueschist and Shale

Blueschist

Shale

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Definition

Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature

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

History

Origin

USA

Discoverer

Edgar Bailey

Johann Gottlob Lehmann

Etymology

From French schiste, Greek skhistos i.e. split

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,

Class

Metamorphic Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Foliated

Clastic, Splintery

Color

Blue, Bluish - Grey, Purple, Shades of Blue

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

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Banded

Muddy

Uses

Architecture

Interior Uses

Floor Tiles, Flooring, Homes, Hotels, Kitchens

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

Garden Decoration, Office Buildings

As Building Stone, As Facing Stone, Office Buildings

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

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

Medical Industry

Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones

Creating Artwork, Pottery

Types

Metamorphic rock

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

Features

Has High structural resistance against erosion and climate, Very fine grained rock

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

Archaeological Significance

Monuments

Famous Monuments

Jantar Mantar in India

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

Formation

Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.

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.

Composition

Mineral Content

Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz

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

Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide

Ca, Fe, Mg, Silicon Dioxide, Sodium

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Mechanical Weathering

Biological Weathering, Chemical Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

Properties

Physical Properties

Hardness

3.5-43

1 7

👆🏻

Grain Size

Fine to Medium Grained

Very fine-grained

Fracture

Conchoidal

Streak

White to Grey

White

Porosity

Highly Porous

Luster

Dull

Compressive Strength

220.00 N/mm²95.00 N/mm²

0.15 450

👆🏻

Cleavage

Slaty

Toughness

1.5

2.6

Specific Gravity

3-3.22.2-2.8

0 8.4

👆🏻

Transparency

Opaque

Density

2.8-2.9 g/cm³2.4-2.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.39 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant

Reserves

Deposits in Eastern Continents

Asia

Japan, Turkey

Bangladesh, China, India, Russia

Africa

Egypt, Ethiopia, South Africa

Ethiopia, Kenya, Morocco, South Africa, Tanzania

Europe

France, Greece, Iceland

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

Others

Deposits in Western Continents

North America

USA

South America

Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela

Deposits in Oceania Continent

Australia

New Zealand

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

All about Blueschist and Shale Properties

Know all about Blueschist and Shale properties here. All properties of rocks are important as they define the type of rock and its application. Blueschist belongs to Metamorphic Rocks while Shale belongs to Sedimentary Rocks.Texture of Blueschist is Foliated whereas that of Shale is Clastic, Splintery. Blueschist appears Dull and Banded and Shale appears Muddy. The luster of Blueschist and Shale is dull. Blueschist is available in blue, bluish - grey, purple, shades of blue colors whereas Shale is available in black, brown, buff, green, grey, red, yellow colors. The commercial uses of Blueschist are cemetery markers, commemorative tablets, creating artwork, curling, tombstones and that of Shale are creating artwork, pottery.