Definition
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
Migmatite is typically a granitic rock within a metamorphic host rock which is composed of two intermingled but distinguishable components
History
Origin
Italy
Southern Alps, France
Discoverer
Unknown
Jakob Sederholm
Etymology
From a Latin word tophous then in Italian tufo and finally tuff
From the Greek word migma which means a mixture
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
-
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Clastic, Pyroclastic
Foliated
Color
Brown, Grey, Yellow
Black, Bluish - Grey, Brown, Brown- Black, Dark Greenish - Grey, Dark Grey to Black
Maintenance
More
More
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Vesicular and Foilated
Dull, Banded and Foilated
Architecture
Interior Uses
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
Countertops, Flooring, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Building houses or walls, Construction Aggregate
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Other Uses
Commercial Uses
Creating Artwork
Cemetery Markers, Jewelry, Tombstones, Used to manufracture paperweights and bookends
Types
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
Diatexites and Metatexites
Features
Always found as volcanic pipes over deep continental crust
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
Migmatites form by high temperature regional and thermal metamorphism of protolith rocks where rocks melt partially due to high temperature.
Composition
Mineral Content
Calcite, Chlorite
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Hydrogen Sulfide, Sulfur Dioxide
Aluminium Oxide, NaCl, CaO, Carbon Dioxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
4-65.5-6.5
1
7
👆🏻
Grain Size
Fine Grained
Medium to Fine Coarse Grained
Fracture
Uneven
Irregular
Streak
White
White
Porosity
Highly Porous
Very Less Porous
Luster
Vitreous to Dull
Dull to Pearly to Subvitreous
Compressive Strength
243.80 N/mm2120.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
1.2
Specific Gravity
2.732.65-2.75
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
1-1.8 g/cm3-9999 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.20 kJ/Kg K0.79 kJ/Kg K
0.14
3.2
👆🏻
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, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Sweden, Switzerland, Ukraine, United Kingdom
Others
Antarctica, Hawaii Islands
-
Deposits in Western Continents
North America
Canada, Costa Rica, Panama, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria