Definition
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
Ignimbrite is a volcanic rock consisting mainly of pumice fragments, formed by the consolidation of material deposited by pyroclastic flows
Origin
Unknown
New Zealand
Discoverer
Alexandre Brongniart and René Just Haüy
Patrick Marshall
Etymology
From Greek trakhus rough’ or trakhutēs roughness
From Latin ignis fire + imber, imbr- shower of rain, storm cloud + -ite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Aphanitic
Color
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
Beige, Black, Brown, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded
Dull, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Flooring, Homes, 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, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
Building houses or walls, Construction Aggregate
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Not Available
Not Available
Features
Available in Lots of Colors and Patterns, Is one of the oldest rock, Matrix variable
Always found as volcanic pipes over deep continental crust
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Formation
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.
Ignimbrites are formed from very poorly sorted mixture of volcanic ash or tuff and pumice lapilli, commonly with scattered lithic fragments.
Mineral Content
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
Apatite, Biotite, Calcite, Chlorite, Feldspar, Hematite, Hornblade, Ilmenite, Magnetite, Olivine, Pyroxene, Quartz
Compound Content
Potassium Oxide, Sodium Oxide, Silicon Dioxide
Ca, NaCl
Types of Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional 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, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Not Available
Uneven
Porosity
Less Porous
Highly Porous
Luster
Metallic
Vitreous to Dull
Cleavage
Not Available
Not Available
Toughness
Not Available
Not Available
Specific Gravity
2.7
2.73
Transparency
Opaque
Opaque
Density
2.43-2.45 g/cm3
1-1.8 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
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
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Cameroon, Cape Verde, Chad, Djibouti, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Tanzania, Uganda
Europe
Bulgaria, England, Germany, Norway, Romania, Switzerland
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Others
Not Yet Found
Antarctica, Hawaii Islands
Deposits in Western Continents
North America
USA
Canada, Costa Rica, Panama, USA
South America
Brazil, Chile
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Western Australia
Central Australia, Western Australia