Definition
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Borolanite is a variety of Nepheline Syenite and belongs to igneous rocks and contains nepheline-alkali feldspar pseudomorphs which occur as conspicuous white spots in the dark rock matrix
History
Origin
Indonesia
Scotland
Discoverer
Cornish Gossen
Unknown
Etymology
From Cornish gossen from gos, blood from Old Cornish guit
From Alkalic Igneous complex near Loch Borralan in northwest Scotland
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Plutonic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Rough, Sandy
Granular
Color
Brown, Brown- Black, Gold, Green, Rust
Brown, Buff, Cream, Green, Grey, Pink, White
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull and Banded
Banded and Foilated
Architecture
Interior Uses
Countertops, Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Homes, Interior Decoration
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
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts
Other Uses
Commercial Uses
Cemetery Markers, Commemorative Tablets, Gemstone
Cemetery Markers
Types
Translocated gossan and Leakage gossan
-
Features
Clasts are smooth to touch, Easily splits into thin plates
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Borolanites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Composition
Mineral Content
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Compound Content
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
-
Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
-
Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Wind Erosion
Physical Properties
Hardness
4-55.5-6
1
7
👆🏻
Grain Size
Fine to Medium Grained
Fine Grained
Fracture
Conchoidal
Conchoidal to Uneven
Streak
White to Grey
White
Porosity
Highly Porous
Less Porous
Luster
Metallic
Greasy to Dull
Compressive Strength
-150.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
-
Specific Gravity
2.02.6
0
8.4
👆🏻
Transparency
Opaque
Translucent to Opaque
Density
-9999 g/cm32.6 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.24 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Indonesia, Russia, Singapore, South Korea
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Albania, France, Germany, Great Britain, United Kingdom
Andorra, Finland, France, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Others
-
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Colombia, Ecuador
Brazil, Chile, Colombia, Uruguay, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, South Australia, Western Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia