Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Adakite is an intermediate to felsic volcanic rock that has geochemical characteristics of magma which is said to be formed by partial melting of altered basalt that is subducted below volcanic arcs
Origin
Indonesia
Adak, Aleutian Islands
Discoverer
Cornish Gossen
Defant and Drummond
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
From Adak, Aleutian Islands
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Rough, Sandy
Porphyritic
Color
Brown, Brown- Black, Gold, Green, Rust
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull and Banded
Dull and Soft
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Hotels, Kitchens
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
Whetstones
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Commemorative Tablets, Pottery, Used in aquariums
Types
Translocated gossan and Leakage gossan
Not Available
Features
Clasts are smooth to touch, Easily splits into thin plates
Has High structural resistance against erosion and climate, Host rock for Diamond, Very fine grained rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Figurines
Not Yet Used
Used
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Adakite rocks are formed when the hydrous fluids are released from minerals that break down in metamorphosed basalt, and rise into the mantle they initiate partial melting.
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Aluminium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Not Applicable
Cataclastic Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Fine to Medium Grained
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
Bluish Black
Porosity
Highly Porous
Less Porous
Luster
Metallic
Grainy, Pearly and Vitreous
Cleavage
Not Available
Not Available
Toughness
Not Available
Not Available
Specific Gravity
2.0
Not Available
Transparency
Opaque
Opaque
Density
Not Available
Not Available
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
India, Russia
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Ethiopia, Somalia, South Africa
Europe
Albania, France, Germany, Great Britain, United Kingdom
Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Colombia, Ecuador
Brazil
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
Not Yet Found