Gossan

Obsidian

Gossan and Obsidian

Gossan

Obsidian

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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.

Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly with minimum crystal growth

1.2 History

1.2.1 Origin

Indonesia

Ethiopia

1.2.2 Discoverer

Cornish Gossen

Obsius

1.3 Etymology

From Cornish gossen from gos, blood from Old Cornish guit

From Latin obsidianus, misprint of Obsianus (lapis) (stone) of Obsius

1.4 Class

Metamorphic Rocks

Igneous Rocks

1.4.1 Sub-Class

Durable Rock, Medium Hardness Rock

1.5 Family

1.5.1 Group

Not Applicable

Volcanic

1.6 Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Opaque Rock

2 Texture

2.1 Texture

Rough, Sandy

Glassy

2.2 Color

Brown, Brown- Black, Gold, Green, Rust

Black, Blue, Brown, Green, Orange, Red, Tan, Yellow

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

Shiny

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

3.1.3 Other Architectural Uses

Curbing

Not Yet Used

3.2 Industry

3.2.1 Construction Industry

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

Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points

3.2.2 Medical Industry

Not Yet Used

Surgery

3.3 Antiquity Uses

Artifacts

Artifacts, Jewellery

3.4 Other Uses

3.4.1 Commercial Uses

Cemetery Markers, Commemorative Tablets, Gemstone

Creating Artwork, Mirror, Used in aquariums

4 Types

4.1 Types

Translocated gossan and Leakage gossan

Fireworks Obsidian, Mahogany, Sheen Obsidian, Snowflake obsidian and Velvet Peacock Obsidian

4.2 Features

Clasts are smooth to touch, Easily splits into thin plates

Blocks negativity, Helps to protect against depression

4.3 Archaeological Significance

4.3.1 Monuments

Not Yet Used

4.3.2 Famous Monuments

Not Applicable

4.3.3 Sculpture

Not Yet Used

4.3.4 Famous Sculptures

Not Applicable

4.3.5 Pictographs

Used

4.3.6 Petroglyphs

Used

4.3.7 Figurines

Not Yet 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.

When the lava is released from volcano, it undergoes a very rapid cooling which freezes the mechanisms of crystallization. The result is a volcanic glass with a uniform smooth texture.

5.2 Composition

5.2.1 Mineral Content

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

Not Available

5.2.2 Compound Content

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

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

✔ ✘

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

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, Mechanical Weathering

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

5-5.5

6.1.2 Grain Size

Fine to Medium Grained

Not Applicable

6.1.3 Fracture

Conchoidal

6.1.4 Streak

White to Grey

White

6.1.5 Porosity

Highly Porous

Very Less Porous

6.1.6 Luster

Metallic

Vitreous

6.1.7 Compressive Strength

What Is Flint

⊕

▶

▼

Not Available

Rank: N/A (Overall)▶

0.15 N/mm²

Rank: 33 (Overall)▶

▲

What Is Obsidian

⊕

▶

175 (What Is Grani..)

◀ ▶ ADD ⊕

6.1.8 Cleavage

Not Available

Non-Existent

6.1.9 Toughness

Not Available

6.1.10 Specific Gravity

2.0

2.6-2.7

6.1.11 Transparency

Opaque

Translucent

6.1.12 Density

Not Available

2.6 g/cm³

6.2 Thermal Properties

6.2.1 Specific Heat Capacity

What Is Banded ..

⊕

▶

▼

0.24 kJ/Kg K

Rank: 24 (Overall)▶

0.92 kJ/Kg K

Rank: 10 (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

Afghanistan, Indonesia, Japan, Russia

7.1.2 Africa

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

Kenya

7.1.3 Europe

Albania, France, Germany, Great Britain, United Kingdom

Greece, Hungary, Iceland, Italy, Turkey

7.1.4 Others

Not Yet Found

7.2 Deposits in Western Continents

7.2.1 North America

Canada, USA

Canada, Mexico, USA

7.2.2 South America

Brazil, Colombia, Ecuador

Argentina, Chile, Ecuador, Peru

7.3 Deposits in Oceania Continent

7.3.1 Australia

New South Wales, South Australia, Western Australia

New Zealand

All about Gossan and Obsidian Properties

Know all about Gossan and Obsidian properties here. All properties of rocks are important as they define the type of rock and its application. Gossan belongs to Metamorphic Rocks while Obsidian belongs to Igneous Rocks.Texture of Gossan is Rough, Sandy whereas that of Obsidian is Glassy. Gossan appears Dull and Banded and Obsidian appears Shiny. The luster of Gossan is metallic while that of Obsidian is vitreous. Gossan is available in brown, brown- black, gold, green, rust colors whereas Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. The commercial uses of Gossan are cemetery markers, commemorative tablets, gemstone and that of Obsidian are creating artwork, mirror, used in aquariums.