Gossan

Ignimbrite

Gossan and Ignimbrite

Gossan

Ignimbrite

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Definition

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

Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows

History

Origin

Indonesia

New Zealand

Discoverer

Cornish Gossen

Patrick Marshall

Etymology

From Cornish gossen from gos, blood from Old Cornish guit

From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite

Class

Metamorphic Rocks

Igneous Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Family

Group

Volcanic

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Rough, Sandy

Aphanitic

Color

Brown, Brown- Black, Gold, Green, Rust

Beige, Black, Brown, Grey, Pink, White

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Banded

Dull, Vesicular and Foilated

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Interior Decoration

Decorative Aggregates, Floor Tiles, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Industry

Construction Industry

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

Building houses or walls, Construction Aggregate

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Gemstone

Cemetery Markers, Commemorative Tablets, Creating Artwork

Types

Translocated gossan and Leakage gossan

Pyroclastic rock

Features

Clasts are smooth to touch, Easily splits into thin plates

Always found as volcanic pipes over deep continental crust

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Formation

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

Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.

Composition

Mineral Content

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

Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz

Compound Content

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

Ca, NaCl

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

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

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion

Properties

Physical Properties

Hardness

4-54-6

1 7

👆🏻

Grain Size

Fine to Medium Grained

Fine Grained

Fracture

Conchoidal

Uneven

Streak

White to Grey

White

Porosity

Highly Porous

Luster

Metallic

Vitreous to Dull

Compressive Strength

-243.80 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.02.73

0 8.4

👆🏻

Transparency

Opaque

Density

-9999 g/cm³1-1.8 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.24 kJ/Kg K0.20 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen

Africa

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

Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda

Europe

Albania, France, Germany, Great Britain, United Kingdom

France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom

Others

Antarctica, Hawaii Islands

Deposits in Western Continents

North America

Canada, USA

Canada, Costa Rica, Panama, USA

South America

Brazil, Colombia, Ecuador

Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador

Deposits in Oceania Continent

Australia

New South Wales, South Australia, Western Australia

Central Australia, Western Australia

All about Gossan and Ignimbrite Properties

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