Gneiss

Eclogite

Gneiss and Eclogite

Gneiss

Eclogite

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Definition

Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks

Eclogite is an extreme metamorphic rock, formed by regional metamorphism of basalt rock under very high pressure and temperature

History

Origin

Discoverer

Unknown

René Just Haüy

Etymology

From the Middle High German verb gneist (to spark; so called because the rock glitters)

From French, Greek eklogē selection with reference to the selective content of the rock + -ite1

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

Family

Group

Other Categories

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Banded, Foliated, Platy

Earthy

Color

Black, Brown, Pink, Red, White

Black, Brown, Green, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Foliated

Dull, Banded and Foilated

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Flooring, Interior Decoration

Decorative Aggregates, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Garden Decoration, Paving Stone

Paving Stone, Garden Decoration

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone

Medical Industry

In Chemical and Pharmaceutical Industry, Medicines and Cosmetics

Antiquity Uses

Artifacts

Other Uses

Commercial Uses

Cemetery Markers, Jewelry, Tombstones, Used in aquariums

Creating Artwork, Gemstone

Types

Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.

Eclogite

Features

Generally rough to touch, Is one of the oldest rock

Available in Lots of Colors and Patterns, Generally rough to touch, Is one of the oldest rock

Archaeological Significance

Monuments

Famous Monuments

Konark Sun Temple in India, Washington Monument, US

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.

Eclogite forms from high-pressure metamorphism of mafic igneous rocks mainly, basalt or gabbro as it plunges into the mantle in a subduction zone.

Composition

Mineral Content

Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon

Amphibole, Coesite, Corundum, Dolomite, Garnet, Kyanite, Lawsonite, Paragonite, Phengite, Pyroxene, Quartz, Rutile, Zoisite

Compound Content

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

Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, Magnesium Carbonate, MgO, Sodium Oxide, Potassium, Sodium

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Mechanical Weathering

Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Sea Erosion

Chemical Erosion, Sea Erosion

Properties

Physical Properties

Hardness

73.5-4

1 7

👆🏻

Grain Size

Medium to Coarse Grained

Fine Grained

Fracture

Irregular

Streak

White

Porosity

Very Less Porous

Less Porous

Luster

Dull

Subvitreous to Dull

Compressive Strength

125.00 N/mm²200.00 N/mm²

0.15 450

👆🏻

Cleavage

Perfect

Toughness

1.2

Specific Gravity

2.5-2.72.86-2.87

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.6-2.9 g/cm³3.2-3.6 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K0.75 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia

India, Kazakhstan, Kuwait, Russia, South Korea, Thailand, Turkey

Africa

Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo

Ethiopia, Morocco, South Africa

Europe

Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom

France, Germany, Italy, Norway, Scotland

Others

Greenland

Deposits in Western Continents

North America

Canada, Costa Rica, Cuba, Mexico, Panama, USA

Canada, Costa Rica, Panama, USA

South America

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

Argentina, Brazil, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Victoria

Central Australia, New Zealand, Queensland

All about Gneiss and Eclogite Properties

Know all about Gneiss and Eclogite properties here. All properties of rocks are important as they define the type of rock and its application. Gneiss and Eclogite belong to Metamorphic Rocks.Texture of Gneiss is Banded, Foliated, Platy whereas that of Eclogite is Earthy. Gneiss appears Foliated and Eclogite appears Dull, Banded and Foilated. The luster of Gneiss is dull while that of Eclogite is subvitreous to dull. Gneiss is available in black, brown, pink, red, white colors whereas Eclogite is available in black, brown, green, grey, pink, white colors. The commercial uses of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums and that of Eclogite are creating artwork, gemstone.