Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
Discoverer
Cornish Gossen
Christian Leopold von Buch
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
From Greek di + base
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Rough, Sandy
Aphanitic, Granular
Color
Brown, Brown- Black, Gold, Green, Rust
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Banded
Vesicular
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Translocated gossan and Leakage gossan
Dolerite
Features
Clasts are smooth to touch, Easily splits into thin plates
Smooth to touch
Archaeological Significance
Famous Monuments
-
Stonehenge in English county of Wiltshire
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Fine to Medium Grained
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
Black
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.0
2.86-2.87
Transparency
Opaque
Opaque
Density
-9999 g/cm3
2.7-3.3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
India
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
South Africa, Tanzania
Europe
Albania, France, Germany, Great Britain, United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Others
-
Antarctica, Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Colombia, Ecuador
Argentina, Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
Central Australia, New Zealand, Queensland, Western Australia