Gossan

Porphyry

Gossan and Porphyry

Gossan

Porphyry

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1 Definition

1.1 Definition

Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.

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

1.2 History

1.2.1 Origin

Indonesia

Egypt

1.2.2 Discoverer

Cornish Gossen

Unknown

1.3 Etymology

From Cornish gossen from gos, blood from Old Cornish guit

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

1.4 Class

Metamorphic Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Hard Rock

1.5 Family

1.5.1 Group

Not Applicable

Plutonic

1.6 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

2 Texture

2.1 Texture

Rough, Sandy

Porphyritic

2.2 Color

Brown, Brown- Black, Gold, Green, Rust

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

2.3 Maintenance

Less

2.4 Durability

Durable

2.4.1 Water Resistant

✔ ✘

81% Metamorphic Rocks Rocks have it !

✔ ✘

81% Igneous Rocks Rocks have it !

2.4.2 Scratch Resistant

✔ ✘

65% Metamorphic Rocks Rocks have it !

✔ ✘

86% Igneous Rocks Rocks have it !

2.4.3 Stain Resistant

✔ ✘

42% Metamorphic Rocks Rocks have it !

✔ ✘

66% Igneous Rocks Rocks have it !

2.4.4 Wind Resistant

✔ ✘

19% Metamorphic Rocks Rocks have it !

✔ ✘

49% Igneous Rocks Rocks have it !

2.4.5 Acid Resistant

✔ ✘

15% Metamorphic Rocks Rocks have it !

✔ ✘

48% Igneous Rocks Rocks have it !

2.5 Appearance

Dull and Banded

Dull

3 Uses

3.1 Architecture

3.1.1 Interior Uses

Countertops, Decorative Aggregates, Interior Decoration

Decorative Aggregates, Interior Decoration

3.1.2 Exterior Uses

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

Garden Decoration, Paving Stone

3.1.3 Other Architectural Uses

Curbing

3.2 Industry

3.2.1 Construction Industry

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate

Construction Aggregate

3.2.2 Medical Industry

Not Yet Used

3.3 Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Commemorative Tablets, Gemstone

Creating Artwork, Gemstone, Jewelry

4 Types

4.1 Types

Translocated gossan and Leakage gossan

Rhomb Porphyry

4.2 Features

Clasts are smooth to touch, Easily splits into thin plates

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

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

Used

4.3.2 Famous Monuments

Not Applicable

Data Not Available

4.3.3 Sculpture

Not Yet Used

Used

4.3.4 Famous Sculptures

Not Applicable

Data Not Available

4.3.5 Pictographs

Used

Not Used

4.3.6 Petroglyphs

Used

Not Used

4.3.7 Figurines

Not Yet Used

Used

4.4 Fossils

Absent

5 Formation

5.1 Formation

Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.

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.

5.2 Composition

5.2.1 Mineral Content

Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon

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

5.2.2 Compound Content

Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur

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

5.3 Transformation

5.3.1 Metamorphism

✔ ✘

50% Metamorphic Rocks Rocks have it !

✔ ✘

97% Igneous Rocks Rocks have it !

5.3.2 Types of Metamorphism

Not Applicable

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

5.3.3 Weathering

✔ ✘

65% Metamorphic Rocks Rocks have it !

✔ ✘

99% Igneous Rocks Rocks have it !

5.3.4 Types of Weathering

Not Applicable

Biological Weathering, Chemical Weathering, Not Registered

5.3.5 Erosion

✔ ✘

77% Metamorphic Rocks Rocks have it !

✔ ✘

92% Igneous Rocks Rocks have it !

5.3.6 Types of Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Glacier Erosion

6 Properties

6.1 Physical Properties

6.1.1 Hardness

4-5

6-7

6.1.2 Grain Size

Fine to Medium Grained

Fine Grained

6.1.3 Fracture

Conchoidal

Irregular

6.1.4 Streak

White to Grey

White

6.1.5 Porosity

Highly Porous

Less Porous

6.1.6 Luster

Metallic

Dull

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

Not Available

Rank: N/A (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Not Available

Imperfect

6.1.9 Toughness

Not Available

1.7

6.1.10 Specific Gravity

2.0

2.5-4

6.1.11 Transparency

Opaque

Translucent to Opaque

6.1.12 Density

Not Available

2.5-2.52 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.24 kJ/Kg K

Rank: 24 (Overall)▶

Not Available

Rank: N/A (Overall)▶

▲

What Is Granulite

⊕

▶

1.09 (What Is Trave..)

◀ ▶ ADD ⊕

6.2.2 Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant

7 Reserves

7.1 Deposits in Eastern Continents

7.1.1 Asia

China, India, Indonesia, Russia, Singapore, South Korea

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

7.1.2 Africa

Cape Verde, Ethiopia, Ghana, South Africa, Western Africa

Egypt, Ethiopia, Ghana, South Africa

7.1.3 Europe

Albania, France, Germany, Great Britain, United Kingdom

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

7.1.4 Others

Not Yet Found

Greenland

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Cuba, Jamaica, USA

7.2.2 South America

Brazil, Colombia, Ecuador

Bolivia, Brazil, Colombia, Ecuador, Paraguay

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, South Australia, Western Australia

New South Wales, New Zealand, Western Australia

All about Gossan and Porphyry Properties

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