Gneiss

Anthracite

Gneiss and Anthracite

Gneiss

Anthracite

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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

Anthracite is a type of sedimentary rock which is hard and is variety of coal that has high luster

History

Origin

Pennsylvania, U.S.

Discoverer

Unknown

Etymology

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

From Greek anthrakites, from anthrax, anthrak meaning coal

Class

Metamorphic Rocks

Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

Family

Group

Other Categories

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Banded, Foliated, Platy

Amorphous, Glassy

Color

Black, Brown, Pink, Red, White

Black, Brown, Dark Brown, Grey, Light to Dark Grey

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Foliated

Veined or Pebbled

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

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

Other Architectural Uses

Curbing

Industry

Construction Industry

As Dimension Stone

Cement Manufacture, for Road Aggregate, Making natural cement, Steel Production

Medical Industry

In Chemical and Pharmaceutical Industry, Manufacture of Aspirins

Antiquity Uses

Artifacts

Other Uses

Commercial Uses

Cemetery Markers, Jewelry, Tombstones, Used in aquariums

Alumina Refineries, Electricity Generation, Liquid Fuel, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Paper Industry

Types

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

Semi-anthracite and Meta-anthracite

Features

Generally rough to touch, Is one of the oldest rock

Helps in production of Heat and Electricity, Used as fossil fuel

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.

Anthracite forms from the accumulation of plant debris in a swamp environment. When plant debris dies and falls into the swamp, the standing water of the swamp protects it from decay.

Composition

Mineral Content

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

Calcite, Clay, Clay Minerals

Compound Content

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

Carbon, Hydrogen, Nitrogen, Oxygen, Sulphur

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Impact Metamorphism

Burial Metamorphism, Contact Metamorphism, Regional Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Coastal Erosion, Sea Erosion

Properties

Physical Properties

Hardness

71-1.5

1 7

👆🏻

Grain Size

Medium to Coarse Grained

Medium to Fine Coarse Grained

Fracture

Irregular

Conchoidal

Streak

White

Black

Porosity

Very Less Porous

Less Porous

Luster

Dull

Shiny

Compressive Strength

125.00 N/mm²-

0.15 450

👆🏻

Cleavage

Toughness

1.2

Specific Gravity

2.5-2.71.1-1.4

0 8.4

👆🏻

Transparency

Translucent to Opaque

Opaque

Density

2.6-2.9 g/cm³1.25-2.5 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.70 kJ/Kg K1.32 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

Heat Resistant, Water Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Bangladesh, Burma, Cambodia, China, India, Indonesia, Kazakhstan, Malaysia, Mongolia, Pakistan, Turkey, Vietnam

Africa

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

Botswana, Kenya, Morocco, Mozambique, South Africa, Tanzania

Europe

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

Belgium, Bulgaria, England, France, Germany, Greece, Hungary, Kosovo, Netherlands, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, The Czech Republic, Ukraine, United Kingdom

Others

Deposits in Western Continents

North America

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

Canada, Mexico, USA

South America

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

Brazil, Chile, Colombia, Venezuela

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Victoria

New South Wales, Queensland, Victoria

All about Gneiss and Anthracite Properties

Know all about Gneiss and Anthracite properties here. All properties of rocks are important as they define the type of rock and its application. Gneiss and Anthracite belong to Metamorphic Rocks.Texture of Gneiss is Banded, Foliated, Platy whereas that of Anthracite is Amorphous, Glassy. Gneiss appears Foliated and Anthracite appears Veined or Pebbled. The luster of Gneiss is dull while that of Anthracite is shiny. Gneiss is available in black, brown, pink, red, white colors whereas Anthracite is available in black, brown, dark brown, grey, light to dark grey colors. The commercial uses of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums and that of Anthracite are alumina refineries, electricity generation, liquid fuel, manufacture of soap, solvents, dyes, plastics and fibres, paper industry.