Adakite

Gneiss

Adakite and Gneiss

Adakite

Gneiss

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Definition

Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs

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

History

Origin

Adak, Aleutian Islands

Discoverer

Defant and Drummond

Unknown

Etymology

From Adak, Aleutian Islands

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

Class

Igneous Rocks

Metamorphic Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

Texture

Porphyritic

Banded, Foliated, Platy

Color

Black, Brown, Light to Dark Grey

Black, Brown, Pink, Red, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Soft

Foliated

Uses

Architecture

Interior Uses

Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens

Countertops, Decorative Aggregates, Flooring, Interior Decoration

Exterior Uses

As Building Stone, As Facing Stone, Office Buildings

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

Other Architectural Uses

Whetstones

Curbing

Industry

Construction Industry

As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone

As Dimension Stone

Medical Industry

Antiquity Uses

Monuments, Sculpture, Small Figurines

Artifacts

Other Uses

Commercial Uses

Commemorative Tablets, Pottery, Used in aquariums

Cemetery Markers, Jewelry, Tombstones, Used in aquariums

Types

Intermediate volcanic rock

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

Features

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

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

Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.

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.

Composition

Mineral Content

Olivine, Plagioclase, Pyroxene

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

Compound Content

Aluminium Oxide, MgO, Silicon Dioxide

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

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism

Impact Metamorphism

Weathering

✔ ✘

Types of Weathering

Chemical Weathering, Mechanical Weathering

Biological Weathering, Mechanical Weathering

Erosion

✔ ✘

Types of Erosion

Coastal Erosion, Sea Erosion, Water Erosion

Chemical Erosion, Coastal Erosion, Sea Erosion

Properties

Physical Properties

Hardness

3-47

1 7

👆🏻

Grain Size

Fine to Medium Grained

Medium to Coarse Grained

Fracture

Conchoidal

Irregular

Streak

Bluish Black

White

Porosity

Less Porous

Very Less Porous

Luster

Grainy, Pearly and Vitreous

Dull

Compressive Strength

200.00 N/mm²125.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

1.2

Specific Gravity

-99992.5-2.7

0 8.4

👆🏻

Transparency

Opaque

Translucent to Opaque

Density

-9999 g/cm³2.6-2.9 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.84 kJ/Kg K0.70 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Pressure Resistant, Wear Resistant

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

India, Russia

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

Africa

Ethiopia, Somalia, South Africa

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

Europe

Iceland

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

Others

Deposits in Western Continents

North America

Canada, USA

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

South America

Brazil

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

Deposits in Oceania Continent

Australia

New South Wales, New Zealand, Queensland, Victoria

All about Adakite and Gneiss Properties

Know all about Adakite and Gneiss properties here. All properties of rocks are important as they define the type of rock and its application. Adakite belongs to Igneous Rocks while Gneiss belongs to Metamorphic Rocks.Texture of Adakite is Porphyritic whereas that of Gneiss is Banded, Foliated, Platy. Adakite appears Dull and Soft and Gneiss appears Foliated. The luster of Adakite is grainy, pearly and vitreous while that of Gneiss is dull. Adakite is available in black, brown, light to dark grey colors whereas Gneiss is available in black, brown, pink, red, white colors. The commercial uses of Adakite are commemorative tablets, pottery, used in aquariums and that of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums.