Chert and Gossan
Definition
Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
History
Origin
Unknown
Indonesia
Discoverer
Unknown
Cornish Gossen
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From Cornish gossen from gos, blood from Old Cornish guit
Class
Sedimentary Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Texture
Banded, Rough
Rough, Sandy
Color
Black, Brown, Green, Grey, Red, White
Brown, Brown- Black, Gold, Green, Rust
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
Yes
Yes
Scratch Resistant
Yes
Yes
Stain Resistant
Yes
Yes
Wind Resistant
No
No
Acid Resistant
Yes
No
Appearance
Glassy or Pearly
Dull and Banded
Uses
Architecture
Interior Uses
Decorative Aggregates, Homes
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Other Uses
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Cemetery Markers, Commemorative Tablets, Gemstone
Types
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Translocated gossan and Leakage gossan
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Clasts are smooth to touch, Easily splits into thin plates
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Not Yet Used
Fossils
Present
Absent
Formation
Formation
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Composition
Mineral Content
Quartz, Silicon
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Compound Content
Silicon Dioxide
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Transformation
Metamorphism
No
No
Types of Metamorphism
Not Applicable
Not Applicable
Weathering
No
No
Types of Weathering
Not Applicable
Not Applicable
Erosion
Yes
Yes
Types of Erosion
Chemical Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Properties
Physical Properties
Hardness
6.5-7
4-5
Grain Size
Very fine-grained
Fine to Medium Grained
Fracture
Uneven, Splintery or Conchoidal
Conchoidal
Streak
White
White to Grey
Porosity
Highly Porous
Highly Porous
Luster
Waxy and Dull
Metallic
Compressive Strength
450.00 N/mm2
1
Not Available
Cleavage
Non-Existent
Not Available
Toughness
1.5
Not Available
Specific Gravity
2.5-2.8
2.0
Transparency
Translucent to Opaque
Opaque
Density
2.7 g/cm3
Not Available
Thermal Properties
Specific Heat Capacity
0.74 kJ/Kg K
19
0.24 kJ/Kg K
24
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Reserves
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Indonesia, Russia, Singapore, South Korea
Africa
Kenya, Morocco, South Africa, Tanzania
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Albania, France, Germany, Great Britain, United Kingdom
Others
Greenland, Mid-Atlantic Ridge
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Bolivia, Brazil
Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New South Wales, South Australia, Western Australia
All about Chert and Gossan Properties
Know all about Chert and Gossan properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Gossan belongs to Metamorphic Rocks.Texture of Chert is Banded, Rough whereas that of Gossan is Rough, Sandy. Chert appears Glassy or Pearly and Gossan appears Dull and Banded. The luster of Chert is waxy and dull while that of Gossan is metallic. Chert is available in black, brown, green, grey, red, white colors whereas Gossan is available in brown, brown- black, gold, green, rust colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Gossan are cemetery markers, commemorative tablets, gemstone.
|
||
|
||
|
