Definition
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
It is a metamorphic magnesium rich rock because it is composed of the mineral talc
Discoverer
Patrick Marshall
Unknown
Etymology
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
From 17th century, because of its greasy feel and use like a soap
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic
Polished
Color
Beige, Black, Brown, Grey, Pink, White
Black, Black to Grey, Green, Grey
Durability
Durable
Durable
Appearance
Dull, Vesicular and Foilated
Dull, Banded and Foilated
Interior Uses
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Bathrooms, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
Manufacture of Magnesium and Dolomite Refractories
Medical Industry
Not Yet Used
Taken as a Supplement for Calcium or Magnesium
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Cemetery Markers, Creating Artwork, Gemstone, Jewelry, Manufacture of Soap, Solvents, Dyes, Plastics and Fibres, Production of Lime, Source of Magnesia (MgO)
Types
Not Available
Not Available
Features
Always found as volcanic pipes over deep continental crust
Host Rock for Lead
Archaeological Significance
Famous Monuments
Data Not Available
Christ the Redeemer in Rio de Janeiro, Stonehenge in English county of Wiltshire
Famous Sculptures
Data Not Available
Data Not Available
Formation
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Soapstone is a talc-schist, which is a type of metamorphic rock and it is largely composed of the mineral talc and is thus rich inmagnesium.
Mineral Content
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Albite, Apatite, Biotite, Calcite, Carbonate, Clay Minerals, Hornblende, Ilmenite, Micas, Plagioclase, Pyroxene, Quartz
Compound Content
Ca, NaCl
CaO, Mg, MgO
Types of Metamorphism
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Not Applicable
Types of Erosion
Chemical Erosion, Coastal Erosion
Not Applicable
Grain Size
Fine Grained
Fine Grained
Fracture
Uneven
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Vitreous to Dull
Greasy
Cleavage
Not Available
Perfect
Toughness
Not Available
1
Specific Gravity
2.73
2.86
Transparency
Opaque
Opaque
Density
1-1.8 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
China, India, Indonesia, Japan, North Korea, Russia, Saudi Arabia, Singapore, South Korea, Sri Lanka, Tajikistan, Thailand
Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Egypt, Ethiopia, Ghana, South Africa, Western Africa
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Austria, England, Finland, France, Germany, Greece, Spain, Sweden, Switzerland, United Kingdom
Others
Antarctica, Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada, USA
South America
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Colombia
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Central Australia, New Zealand, Queensland