Gneiss

Gabbro

Gneiss and Gabbro

Gneiss

Gabbro

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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

Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt

History

Origin

Germany

Discoverer

Unknown

Christian Leopold von Buch

Etymology

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

From Latin glaber bare, smooth, bald

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Hard Rock

Family

Group

Plutonic

Other Categories

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Opaque Rock

Texture

Banded, Foliated, Platy

Phaneritic

Color

Black, Brown, Pink, Red, White

Dark Grey to Black

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Foliated

Veined and Shiny

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Flooring, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone

As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

Other Uses

Commercial Uses

Cemetery Markers, Jewelry, Tombstones, Used in aquariums

Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones

Types

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

Anorthosite Gabbro and Norite Gabbro

Features

Generally rough to touch, Is one of the oldest rock

Smooth to touch

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.

Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.

Composition

Mineral Content

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

Augite, Olivine, Plagioclase, Pyroxene

Compound Content

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

Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Mechanical Weathering

Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Sea Erosion

Coastal Erosion

Properties

Physical Properties

Hardness

1 7

👆🏻

Grain Size

Medium to Coarse Grained

Coarse Grained

Fracture

Irregular

Conchoidal

Streak

White

Black

Porosity

Very Less Porous

Highly Porous

Luster

Dull

Compressive Strength

125.00 N/mm²225.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.2

1.6

Specific Gravity

2.5-2.72.86-2.87

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.6-2.9 g/cm³2.7-3.3 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K0.71 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

India, Russia

Africa

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

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

Germany, Greece, Italy, Scotland, Turkey

Others

Greenland

Deposits in Western Continents

North America

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

Canada, USA

South America

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

Brazil, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Victoria

New Zealand, Queensland

All about Gneiss and Gabbro Properties

Know all about Gneiss and Gabbro properties here. All properties of rocks are important as they define the type of rock and its application. Gneiss belongs to Metamorphic Rocks while Gabbro belongs to Igneous Rocks.Texture of Gneiss is Banded, Foliated, Platy whereas that of Gabbro is Phaneritic. Gneiss appears Foliated and Gabbro appears Veined and Shiny. The luster of Gneiss is dull while that of Gabbro is . Gneiss is available in black, brown, pink, red, white colors whereas Gabbro is available in dark grey to black colors. The commercial uses of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums and that of Gabbro are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.