Gossan

Chalk

Gossan and Chalk

Gossan

Chalk

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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.

Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers

History

Origin

Indonesia

Discoverer

Cornish Gossen

Unknown

Etymology

From Cornish gossen from gos, blood from Old Cornish guit

From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone

Class

Metamorphic Rocks

Sedimentary Rocks

Sub-Class

Durable Rock, Medium Hardness Rock

Durable Rock, Soft Rock

Family

Group

Other Categories

Fine Grained Rock, Medium Grained Rock, Opaque Rock

Fine Grained Rock, Opaque Rock

Texture

Rough, Sandy

Clastic or Non-Clastic

Color

Brown, Brown- Black, Gold, Green, Rust

Grey, White, Yellow

Maintenance

Less

Durability

Durable

Water Resistant

✔ ✘

Scratch Resistant

✔ ✘

Stain Resistant

✔ ✘

Wind Resistant

✔ ✘

Acid Resistant

✔ ✘

Appearance

Dull and Banded

Soft

Uses

Architecture

Interior Uses

Countertops, Decorative Aggregates, Interior Decoration

Decorative Aggregates, Homes, Interior Decoration

Exterior Uses

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

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

Other Architectural Uses

Curbing

Powder

Industry

Construction Industry

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

As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium

Medical Industry

Antiquity Uses

Artifacts

Artifacts, Monuments, Sculpture, Small Figurines

Other Uses

Commercial Uses

Cemetery Markers, Commemorative Tablets, Gemstone

Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper

Types

Translocated gossan and Leakage gossan

Chalk Marl and Marl

Features

Clasts are smooth to touch, Easily splits into thin plates

Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock

Archaeological Significance

Monuments

Famous Monuments

Sculpture

Famous Sculptures

Pictographs

Petroglyphs

Figurines

Fossils

Absent

Present

Formation

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

Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.

Composition

Mineral Content

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

Calcite, Clay, Clay Minerals, Quartz, Sand

Compound Content

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

Ca, NaCl, CaO

Transformation

Metamorphism

✔ ✘

Types of Metamorphism

Weathering

✔ ✘

Types of Weathering

Biological Weathering, Chemical Weathering

Erosion

✔ ✘

Types of Erosion

Chemical Erosion, Sea Erosion, Wind Erosion

Chemical Erosion, Coastal Erosion, Water Erosion

Properties

Physical Properties

Hardness

4-51

1 7

👆🏻

Grain Size

Fine to Medium Grained

Very fine-grained

Fracture

Conchoidal

Streak

White to Grey

White

Porosity

Highly Porous

Luster

Metallic

Dull

Compressive Strength

-5.00 N/mm²

0.15 450

👆🏻

Cleavage

Toughness

Specific Gravity

2.02.3-2.4

0 8.4

👆🏻

Transparency

Opaque

Density

-9999 g/cm³2.49-2.50 g/cm³

0 1400

👆🏻

Thermal Properties

Specific Heat Capacity

0.24 kJ/Kg K0.90 kJ/Kg K

0.14 3.2

👆🏻

Resistance

Heat Resistant, Impact Resistant, Pressure Resistant

Heat Resistant

Reserves

Deposits in Eastern Continents

Asia

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

Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam

Africa

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

Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe

Europe

Albania, France, Germany, Great Britain, United Kingdom

England, France, Germany, Spain, United Kingdom

Others

Deposits in Western Continents

North America

Canada, USA

South America

Brazil, Colombia, Ecuador

Colombia

Deposits in Oceania Continent

Australia

New South Wales, South Australia, Western Australia

Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula

All about Gossan and Chalk Properties

Know all about Gossan and Chalk properties here. All properties of rocks are important as they define the type of rock and its application. Gossan belongs to Metamorphic Rocks while Chalk belongs to Sedimentary Rocks.Texture of Gossan is Rough, Sandy whereas that of Chalk is Clastic or Non-Clastic. Gossan appears Dull and Banded and Chalk appears Soft. The luster of Gossan is metallic while that of Chalk is dull. Gossan is available in brown, brown- black, gold, green, rust colors whereas Chalk is available in grey, white, yellow colors. The commercial uses of Gossan are cemetery markers, commemorative tablets, gemstone and that of Chalk are alumina refineries, creating artwork, drawing on blackboards, gymnasts, athletes and mountain climbers use for grip, in aquifers, paper industry, production of lime, raw material for manufacture of quicklime, slaked lime, soil conditioner, whiting, whiting material in toothpaste, paint and paper.