Porphyry

Hornfels

Porphyry and Hornfels

Porphyry

Hornfels

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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

Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock

1.2 History

1.2.1 Origin

Egypt

New Zealand

1.2.2 Discoverer

Unknown

1.3 Etymology

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

From German which means hornstone

1.4 Class

Igneous Rocks

Metamorphic Rocks

1.4.1 Sub-Class

Durable Rock, Hard Rock

Durable Rock, Soft Rock

1.5 Family

1.5.1 Group

Plutonic

Not Applicable

1.6 Other Categories

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Porphyritic

Granular, Platy

2.2 Color

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

Brown, Dark Greenish - Grey, Green, Reddish Brown

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

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Decorative Aggregates, Interior Decoration

Decorative Aggregates, Flooring, Homes, Interior Decoration

3.1.2 Exterior Uses

Garden Decoration, Paving Stone

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

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

Construction Aggregate

for Road Aggregate, Roadstone

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts, Monuments, Sculpture

Artifacts, Monuments

3.4 Other Uses

3.4.1 Commercial Uses

Creating Artwork, Gemstone, Jewelry

Cemetery Markers, Commemorative Tablets, Creating Artwork

4 Types

4.1 Types

Rhomb Porphyry

Biotite hornfels

4.2 Features

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

Smooth to touch

4.3 Archaeological Significance

4.3.1 Monuments

Used

4.3.2 Famous Monuments

Data Not Available

4.3.3 Sculpture

Used

Not Yet Used

4.3.4 Famous Sculptures

Data Not Available

Not Applicable

4.3.5 Pictographs

Not Used

Used

4.3.6 Petroglyphs

Not Used

Used

4.3.7 Figurines

Used

Not Yet 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.

Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.

5.2 Composition

5.2.1 Mineral Content

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

Andalusite

5.2.2 Compound Content

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

Fe, Mg

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

Not Applicable

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, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

6-72-3

1 7

6.1.2 Grain Size

Fine Grained

6.1.3 Fracture

Irregular

Conchoidal

6.1.4 Streak

White

Unknown

6.1.5 Porosity

Less Porous

Highly Porous

6.1.6 Luster

Dull

Shiny

6.1.7 Compressive Strength

NA5.80 N/mm²

0.15 450

6.1.8 Cleavage

Imperfect

Perfect

6.1.9 Toughness

1.7

Not Yet Found

6.1.10 Specific Gravity

2.5-43.4-3.9

0 8.4

6.1.11 Transparency

Translucent to Opaque

Opaque

6.1.12 Density

2.5-2.52 g/cm³0.25-0.30 g/cm³

0 1400

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

NA0.84 kJ/Kg K

0.14 3.2

6.2.2 Resistance

Heat Resistant, Impact Resistant

Heat Resistant, Impact Resistant, Pressure Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

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

Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand

7.1.2 Africa

Egypt, Ethiopia, Ghana, South Africa

Cameroon, East Africa, Tanzania, Western Africa

7.1.3 Europe

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

United Kingdom

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

Bolivia, Brazil, Colombia, Ecuador

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, New Zealand, Western Australia

New South Wales, New Zealand, Queensland, Western Australia

All about Porphyry and Hornfels Properties

Know all about Porphyry and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Porphyry belongs to Igneous Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Porphyry is Porphyritic whereas that of Hornfels is Granular, Platy. Porphyry appears Dull and Hornfels appears Dull. The luster of Porphyry is dull while that of Hornfels is shiny. Porphyry is available in black, brown, colourless, green, grey, red, rust, white colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Porphyry are creating artwork, gemstone, jewelry and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.