Definition
Breccia is a rock consisting of angular fragments of stones which are cemented by finer calcareous material
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
Origin
England
New Zealand
Discoverer
Unknown
Patrick Marshall
Etymology
From Italian, literally gravel, Germanic origin and related to break
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Brecciated, Clastic
Aphanitic
Color
Beige, Black, Blue, Brown, Buff, Green, Grey, Orange, Pink, Purple, Red, Rust, White, Yellow
Beige, Black, Brown, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Layered, Banded, Veined and Shiny
Dull, Vesicular and Foilated
Interior Uses
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration
Decorative Aggregates, Floor Tiles, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, Landscaping, Roadstone
Building houses or walls, Construction Aggregate
Antiquity Uses
Artifacts, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, Jewelry
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Collapse Breccia, Fault Breccia, Flow Breccia, Pyroclastic Breccia, Igneous Breccia and Impact Breccia
Pyroclastic rock
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Always found as volcanic pipes over deep continental crust
Archaeological Significance
Formation
Breccia is a clastic sedimentary rock which is composed of broken fragments of minerals or rock which are cemented together by a fine-grained matrix and it forms where broken, angular fragments of rock or mineral debris accumulate.
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Mineral Content
Calcite, Clay, Feldspar, Phosphates, Quartz, Silica
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Compound Content
Aluminium Oxide, Ca, NaCl, CaO, Iron(III) Oxide, Potassium Oxide, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Ca, NaCl
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Medium to Coarse Grained
Fine Grained
Porosity
Less Porous
Highly Porous
Luster
Dull to Pearly
Vitreous to Dull
Specific Gravity
2.86-2.87
2.73
Transparency
Opaque
Opaque
Density
0 g/cm3
1-1.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Kazakhstan, Mongolia, Russia, South Korea, Uzbekistan
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
Africa
Namibia, Nigeria, South Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Europe
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
Greenland
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
Barbados, Canada, Mexico, Panama, USA
Canada, Costa Rica, Panama, USA
South America
Brazil
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New South Wales, New Zealand
Central Australia, Western Australia