Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Discoverer
Unknown
Cornish Gossen
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From Cornish gossen from gos, blood from Old Cornish guit
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Rough, Sandy
Color
Grey, White, Yellow
Brown, Brown- Black, Gold, Green, Rust
Durability
Durable
Durable
Appearance
Soft
Dull and Banded
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Powder
Curbing
Construction Industry
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
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
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
Cemetery Markers, Commemorative Tablets, Gemstone
Types
Chalk Marl and Marl
Translocated gossan and Leakage gossan
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Clasts are smooth to touch, Easily splits into thin plates
Archaeological Significance
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Compound Content
Ca, NaCl, CaO
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Types of Metamorphism
-
-
Types of Weathering
Biological Weathering, Chemical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Grain Size
Very fine-grained
Fine to Medium Grained
Streak
White
White to Grey
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.3-2.4
2.0
Transparency
Opaque
Opaque
Density
2.49-2.50 g/cm3
-9999 g/cm3
Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
China, India, Indonesia, Russia, Singapore, South Korea
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Europe
England, France, Germany, Spain, United Kingdom
Albania, France, Germany, Great Britain, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
New South Wales, South Australia, Western Australia
All about Chalk and Gossan Properties
Know all about Chalk and Gossan properties here. All properties of rocks are important as they define the type of rock and its application. Chalk belongs to Sedimentary Rocks while Gossan belongs to Metamorphic Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Gossan is Rough, Sandy. Chalk appears Soft and Gossan appears Dull and Banded. The luster of Chalk is dull while that of Gossan is metallic. Chalk is available in grey, white, yellow colors whereas Gossan is available in brown, brown- black, gold, green, rust colors. The commercial uses 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 and that of Gossan are cemetery markers, commemorative tablets, gemstone.