Picrite

Gneiss

Picrite and Gneiss

Picrite

Gneiss

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1 Definition

1.1 Definition

Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine

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

1.2 History

1.2.1 Origin

Hawaii Islands

Unknown

1.2.2 Discoverer

Unknown

1.3 Etymology

From Greek pikros bitter + -ite, 19th century

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

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Volcanic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

Coarse Grained Rock, Medium Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Earthy, Rough

Banded, Foliated, Platy

2.2 Color

Black, Brown, Colourless, Green, Grey, Pink, White, Yellow

Black, Brown, Pink, Red, White

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Igneous Rocks Rocks have it !

✔ ✘

81% Metamorphic Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

86% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

66% Igneous Rocks Rocks have it !

✔ ✘

42% Metamorphic Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

49% Igneous Rocks Rocks have it !

✔ ✘

19% Metamorphic Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

48% Igneous Rocks Rocks have it !

✔ ✘

15% Metamorphic Rocks Rocks have it !

2.5 Appearance

Rough and Shiny

Foliated

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Countertops, Decorative Aggregates, Homes, Interior Decoration

Countertops, Decorative Aggregates, Flooring, Interior Decoration

3.1.2 Exterior Uses

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.

As Dimension Stone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts

3.4 Other Uses

3.4.1 Commercial Uses

As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)

Cemetery Markers, Jewelry, Tombstones, Used in aquariums

4 Types

4.1 Types

Oceanite

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

4.2 Features

Host Rock for Lead

Generally rough to touch, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

Konark Sun Temple in India, Washington Monument, US

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Used

Not Yet Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.

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.

5.2 Composition

5.2.1 Mineral Content

Biotite, Olivine, Plagioclase, Pyrrhotite

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

5.2.2 Compound Content

Al, CaO, Carbon Dioxide, Mg, MgO

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

97% Igneous Rocks Rocks have it !

✔ ✘

50% Metamorphic Rocks Rocks have it !

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Impact Metamorphism

5.3.3 Weathering

✔ ✘

99% Igneous Rocks Rocks have it !

✔ ✘

65% Metamorphic Rocks Rocks have it !

5.3.4 Types of Weathering

Biological Weathering

Biological Weathering, Mechanical Weathering

5.3.5 Erosion

✔ ✘

92% Igneous Rocks Rocks have it !

✔ ✘

77% Metamorphic Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Sea Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.8

6.1.2 Grain Size

Fine Grained

Medium to Coarse Grained

6.1.3 Fracture

Uneven

Irregular

6.1.4 Streak

White, Greenish White or Grey

White

6.1.5 Porosity

Less Porous

Very Less Porous

6.1.6 Luster

Subvitreous to Dull

Dull

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

189.00 N/mm²

Rank: 11 (Overall)▶

125.00 N/mm²

Rank: 17 (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Imperfect

Poor

6.1.9 Toughness

2.1

1.2

6.1.10 Specific Gravity

2.75-2.92

2.5-2.7

6.1.11 Transparency

Opaque

Translucent to Opaque

6.1.12 Density

1.5-2.5 g/cm³

2.6-2.9 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.88 kJ/Kg K

Rank: 13 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant

Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Russia

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

7.1.2 Africa

South Africa

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

7.1.3 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

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

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

7.2.2 South America

Brazil

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

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New South Wales, New Zealand, Queensland, Victoria

All about Picrite and Gneiss Properties

Know all about Picrite and Gneiss properties here. All properties of rocks are important as they define the type of rock and its application. Picrite belongs to Igneous Rocks while Gneiss belongs to Metamorphic Rocks.Texture of Picrite is Earthy, Rough whereas that of Gneiss is Banded, Foliated, Platy. Picrite appears Rough and Shiny and Gneiss appears Foliated. The luster of Picrite is subvitreous to dull while that of Gneiss is dull. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas Gneiss is available in black, brown, pink, red, white colors. The commercial uses of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo) and that of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums.