Porphyry

Picrite

Porphyry and Picrite

Porphyry

Picrite

Add ⊕

1 Definition

1.1 Definition

Porphyry is a reddish-brown to purple igneous rock containing large phenocrysts of various minerals embedded in a fine-grained matrix

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

1.2 History

1.2.1 Origin

Egypt

Hawaii Islands

1.2.2 Discoverer

Unknown

1.3 Etymology

From Old French porfire, from Italian porfiro and in some cases directly from Latin porphyrites

From Greek pikros bitter + -ite, 19th century

1.4 Class

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Plutonic

Volcanic

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Porphyritic

Earthy, Rough

2.2 Color

Black, Brown, Colourless, Green, Grey, Red, Rust, White

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

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

Dull

Rough and Shiny

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Countertops, Decorative Aggregates, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Paving Stone

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

Construction Aggregate

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.

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone, Jewelry

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

4 Types

4.1 Types

Rhomb Porphyry

Oceanite

4.2 Features

Generally rough to touch, Is one of the oldest rock, Surfaces are often shiny

Host Rock for Lead

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

4.3.6 Petroglyphs

Not Used

4.3.7 Figurines

Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Porphyry is formed in two stages: the magma cools slowly deep within the crust or the magma is cools rapidly as it erupts from a volcano, creating small grains that are usually invisible to naked eye.

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.

5.2 Composition

5.2.1 Mineral Content

Biotite, Chert, Feldspar, Garnet, Graphite, Quartz, Silica

Biotite, Olivine, Plagioclase, Pyrrhotite

5.2.2 Compound Content

Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide

Al, CaO, Carbon Dioxide, Mg, MgO

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

5.3.2 Types of Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism

Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism

5.3.3 Weathering

✔ ✘

5.3.4 Types of Weathering

Biological Weathering, Chemical Weathering, Not Registered

Biological Weathering

5.3.5 Erosion

✔ ✘

5.3.6 Types of Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

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

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-76.8

1 7

6.1.2 Grain Size

Fine Grained

6.1.3 Fracture

Irregular

Uneven

6.1.4 Streak

White

White, Greenish White or Grey

6.1.5 Porosity

Less Porous

6.1.6 Luster

Dull

Subvitreous to Dull

6.1.7 Compressive Strength

NA189.00 N/mm²

0.15 450

6.1.8 Cleavage

Imperfect

6.1.9 Toughness

1.7

2.1

6.1.10 Specific Gravity

2.5-42.75-2.92

0 8.4

6.1.11 Transparency

Translucent to Opaque

Opaque

6.1.12 Density

2.5-2.52 g/cm³1.5-2.5 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.88 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, Kazakhstan, South Korea, Thailand, Turkey, Vietnam

India, Russia

7.1.2 Africa

Egypt, Ethiopia, Ghana, South Africa

South Africa

7.1.3 Europe

Finland, France, Germany, Great Britain, Hungary, Iceland, Ireland, Italy, Netherlands, Norway, Romania, Sweden, Switzerland

Iceland

7.1.4 Others

Greenland

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, Cuba, Jamaica, USA

Canada, USA

7.2.2 South America

Bolivia, Brazil, Colombia, Ecuador, Paraguay

Brazil

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand, Western Australia

Not Yet Found

All about Porphyry and Picrite Properties

Know all about Porphyry and Picrite properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry and Picrite belong to Igneous Rocks.Texture of Porphyry is Porphyritic whereas that of Picrite is Earthy, Rough. Porphyry appears Dull and Picrite appears Rough and Shiny. The luster of Porphyry is dull while that of Picrite is subvitreous to dull. Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors whereas Picrite is available in black, brown, colourless, green, grey, pink, white, yellow colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Picrite are as a feed additive for livestock, as armour rock for sea walls, metallurgical flux, pottery, source of magnesia (mgo).