Definition
Boninite is a mafic extrusive rock which is high in magnesium and silica content, formed in fore-arc environments, typically during the early stages of subduction
Shonkinite is a rare, dark-coloured and intrusive igneous rock which contains augite and orthoclase feldspar as its primary constituents
Discoverer
Unknown
Unknown
Etymology
From its occurrence in the Izu-Bonin arc south of Japan
From the name of Shonkin Sag ranges in the Highwood Mountains of north-central Montana, US
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy
Color
Bluish - Grey, Brown, Green, Grey
Brown, Buff, Cream, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Banded and Foilated
Interior Uses
Decorative Aggregates, Homes, Kitchens
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Construction Industry
As a Flux in the Production of Steel and Pig Iron, As a Sintering Agent in Steel Industry to process Iron Ore, As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
An Oil and Gas Reservoir, Cemetery Markers, Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Creating Artwork
Types
Basalt
Igneous rock
Features
Available in Lots of Colors and Patterns, High Mg content, Is one of the oldest rock
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Archaeological Significance
Formation
Boninite is a type of Igneous rock which is formed through the cooling and solidification of lava or existing rocks.
Shonkinites are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Ilmenite
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion, Water Erosion
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Porosity
Less Porous
Less Porous
Luster
Vitreous
Subvitreous to Dull
Specific Gravity
2.5-2.8
2.6-2.7
Transparency
Opaque
Opaque
Density
-9999 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
South Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
England, Finland, United Kingdom
Bulgaria, England, Germany, Norway, Romania, Switzerland
Others
Antarctica, Greenland
-
Deposits in Western Continents
South America
Colombia, Uruguay
Brazil, Chile
Deposits in Oceania Continent
Australia
New Zealand, Western Australia
New Zealand, Queensland, South Australia, Western Australia