Picrite

Nepheline Syenite

Picrite and Nepheline Syenite

Picrite

Nepheline Syenite

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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

Nepheline Syenite is a holocrystalline plutonic rock resembling syenite but containing nepheline and lacking quartz

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 origin of a Palaeozoic nepheline syenite from northern Shanxi Province, China

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Volcanic

Plutonic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Earthy, Rough

Granular

2.2 Color

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

Brown, Buff, Cream, Green, Grey, Pink, White

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

2.4.2 Scratch Resistant

✔ ✘

2.4.3 Stain Resistant

✔ ✘

2.4.4 Wind Resistant

✔ ✘

2.4.5 Acid Resistant

✔ ✘

2.5 Appearance

Rough and Shiny

Banded and Foilated

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Countertops, Decorative Aggregates, Homes, Interior Decoration

Countertops, Decorative Aggregates, Flooring, Homes, 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, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

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, Creating Artwork

4 Types

4.1 Types

Oceanite

Borolanite and Litchfieldite

4.2 Features

Host Rock for Lead

Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

4.3.4 Famous Sculptures

Data Not Available

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

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.

Nepheline Syenites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.

5.2 Composition

5.2.1 Mineral Content

Biotite, Olivine, Plagioclase, Pyrrhotite

Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite

5.2.2 Compound Content

Al, CaO, Carbon Dioxide, Mg, MgO

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Impact Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering

Biological Weathering, Chemical Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

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

Chemical Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6.85.5-6

1 7

6.1.2 Grain Size

Fine Grained

6.1.3 Fracture

Uneven

Conchoidal to Uneven

6.1.4 Streak

White, Greenish White or Grey

White

6.1.5 Porosity

Less Porous

6.1.6 Luster

Subvitreous to Dull

Greasy to Dull

6.1.7 Compressive Strength

189.00 N/mm²150.00 N/mm²

0.15 450

6.1.8 Cleavage

Imperfect

Poor

6.1.9 Toughness

2.1

Not Available

6.1.10 Specific Gravity

2.75-2.922.6

0 8.4

6.1.11 Transparency

Opaque

Translucent to Opaque

6.1.12 Density

1.5-2.5 g/cm³2.6 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

0.88 kJ/Kg KNA

0.14 3.2

6.2.2 Resistance

Heat Resistant

Heat Resistant, Impact Resistant, Wear Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

India, Russia

Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam

7.1.2 Africa

South Africa

Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa

7.1.3 Europe

Iceland

Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden

7.1.4 Others

Not Yet Found

Greenland

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

7.2.2 South America

Brazil

Brazil, Chile, Colombia, Uruguay, Venezuela

7.3 Deposits in Oceania Continent

7.3.1 Australia

Not Yet Found

New Zealand, Queensland, South Australia, Tasmania, Western Australia

All about Picrite and Nepheline Syenite Properties

Know all about Picrite and Nepheline Syenite properties here. All properties of rocks are important as they define the type of rock and its application. Picrite and Nepheline Syenite belong to Igneous Rocks.Texture of Picrite is Earthy, Rough whereas that of Nepheline Syenite is Granular. Picrite appears Rough and Shiny and Nepheline Syenite appears Banded and Foilated. The luster of Picrite is subvitreous to dull while that of Nepheline Syenite is greasy to dull. Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors whereas Nepheline Syenite is available in brown, buff, cream, green, grey, pink, 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 Nepheline Syenite are cemetery markers, creating artwork.