Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Amphibolite can be defined as a granular metamorphic rock which mainly consist of hornblende and plagioclase
Discoverer
Unknown
Alexandre Brongniart
Etymology
From a Latin word tophous then in Italian tufo and finally tuff
From Amphibole + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic, Pyroclastic
Banded, Foliated, Massive
Color
Brown, Grey, Yellow
Black, Brown, Green, Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Vesicular and Foilated
Foliated
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Building houses or walls, Cobblestones, Construction Aggregate, for Road Aggregate, Landscaping, Production of Glass and Ceramics, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Hornblendite
Features
Always found as volcanic pipes over deep continental crust
Clasts are smooth to touch, Matrix variable, Surfaces are often shiny
Archaeological Significance
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean
Data Not Available
Famous Sculptures
Data Not Available
Data Not Available
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Formation
Tuff is formed when large masses of ash and sand which are mixed with hot gases are ejected by a volcano and avalanche rapidly down its slopes.
Amphibolite is a coarse-grained metamorphic rock which forms by metamorphism of mafic igneous rocks like basalt and gabbro or from the metamorphism of clay-rich sedimentary rocks like marl or graywacke.
Mineral Content
Calcite, Chlorite
Amphibole, Andalusite, Biotite, Calcite, Epidote, Garnet, Hornblade, Kyanite, Magnetite, Olivine, Plagioclase, Pyroxene, Staurolite, Wollastonite
Compound Content
Hydrogen Sulfide, Sulfur 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, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Wind Erosion
Grain Size
Fine Grained
Medium to Coarse Grained
Fracture
Uneven
Irregular to Conchoidal
Streak
White
White to Grey
Porosity
Highly Porous
Less Porous
Luster
Vitreous to Dull
Vitreous to Dull
Compressive Strength
Not Available
Cleavage
Not Available
Irregular
Toughness
Not Available
2.3
Specific Gravity
2.73
2.5
Transparency
Opaque
Opaque
Density
1-1.8 g/cm3
2.85-3.07 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Pressure Resistant, Wear 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
Russia, Turkey
Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Rwanda, Somalia, South Africa, Sudan, Tanzania, Uganda
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Germany, Greece, Iceland, Norway, Poland
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, Ecuador, Paraguay
Brazil
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
South Australia, Western Australia