Definition
Ijolite is an intrusive igneous rock which is composed mainly of nepheline and an alkali pyroxene, usually aegirine-augite
Gossan is intensely oxidized, weathered or decomposed rock, usually the upper and exposed part of an ore deposit or mineral vein.
Origin
Finland, Europe
Indonesia
Discoverer
Unknown
Cornish Gossen
Etymology
From the first syllable of the Finnish words Ii-vaara, Iijoki, &c. commonly used geographical names in Finland, and the Gr. Xiflos, a stone
From Cornish gossen from gos, blood from Old Cornish guit
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy, Granular
Rough, Sandy
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Brown, Brown- Black, Gold, Green, Rust
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded and Foilated
Dull and Banded
Interior Uses
Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Interior Decoration, Kitchens
Countertops, Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
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, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Gemstone
Types
Alkaline rock
Translocated gossan and Leakage gossan
Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Is one of the oldest rock
Clasts are smooth to touch, Easily splits into thin plates
Archaeological Significance
Formation
Ijolite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Earth movements can cause rocks to be either deeply buried or squeezed and hence the rocks are heated and put under great pressure.
Mineral Content
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Apatite, Augite, Biotite, Bronzite, Calcite, Chert, Epidote, Feldspar, Hornblende, Micas, Plagioclase, Pyroxene, Quartz, Sulfides, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide
Aluminium Oxide, CaO, Fe, FeO, Silicon Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering
-
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Wind Erosion
Grain Size
Coarse Grained
Fine to Medium Grained
Fracture
Conchoidal to Uneven
Conchoidal
Streak
White
White to Grey
Porosity
Less Porous
Highly Porous
Luster
Greasy to Dull
Metallic
Specific Gravity
2.6-2.76
2.0
Transparency
Opaque
Opaque
Density
2.6 g/cm3
-9999 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
China, India, Indonesia, Russia, Singapore, South Korea
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Cape Verde, Ethiopia, Ghana, South Africa, Western Africa
Europe
England, Finland, Germany, Great Britain, Greece, United Kingdom
Albania, France, Germany, Great Britain, United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
New South Wales, South Australia, Western Australia