Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles
Discoverer
Cornish Gossen
Johann Gottlob Lehmann
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
From German Schalstein laminated limestone, and Schalgebirge layer of stone in stratified rock. From Old English scealu in its base sense of- thing that divides or separate,
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Rough, Sandy
Clastic, Splintery
Color
Brown, Brown- Black, Gold, Green, Rust
Black, Brown, Buff, Green, Grey, Red, Yellow
Durability
Durable
Durable
Appearance
Dull and Banded
Muddy
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, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, Raw material for the manufacture of mortar
Antiquity Uses
Artifacts
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Creating Artwork, Pottery
Types
Translocated gossan and Leakage gossan
Red Shale, Black Shale, Green Shale, Grey Shale and Yellow Shale
Features
Clasts are smooth to touch, Easily splits into thin plates
Easily splits into thin plates, Generally rough to touch, Very fine grained rock
Archaeological Significance
Famous Monuments
-
Jantar Mantar in India
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Shale forms when very fine-grained clay particles are deposited in water which settle at the bottom of water bodies. They are later compacted hence forming shale.
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Albite, Biotite, Calcite, Chert, Chlorite, Dolomite, Hematite, Micas, Muscovite or Illite, Pyrite, Quartz, Silica, Sulfides
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Ca, Fe, Mg, Silicon Dioxide, Sodium
Types of Metamorphism
-
-
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine to Medium Grained
Very fine-grained
Streak
White to Grey
White
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.0
2.2-2.8
Transparency
Opaque
Opaque
Density
-9999 g/cm3
2.4-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
Bangladesh, China, India, Russia
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Albania, France, Germany, Great Britain, United Kingdom
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil, Colombia, Ecuador
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria, Western Australia