1 Definition
1.1 Definition
Picrite is a variety of high-magnesium olivine basalt that is very rich in the mineral olivine
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption
1.2 History
1.2.1 Origin
1.2.2 Discoverer
1.3 Etymology
From Greek pikros bitter + -ite, 19th century
From a Latin word tophous then in Italian tufo and finally tuff
1.4 Class
Igneous Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Earthy, Rough
Clastic, Pyroclastic
2.2 Color
Black, Brown, Colourless, Green, Grey, Pink, White, Yellow
Brown, Grey, Yellow
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
Rough and Shiny
Dull, Vesicular and Foilated
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As a Sintering Agent in Steel Industry to process Iron Ore, Cement Manufacture, for Road Aggregate, Manufacture of Magnesium and Dolomite Refractories, Roadstone, Used for flooring, stair treads, borders and window sills.
Building houses or walls, Construction Aggregate
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
3.4 Other Uses
3.4.1 Commercial Uses
As a Feed Additive for Livestock, As armour rock for sea walls, Metallurgical Flux, Pottery, Source of Magnesia (MgO)
Creating Artwork
4 Types
4.1 Types
Oceanite
Welded tuff, Rhyolitic tuff, Basaltic tuff, Trachyte tuff, Andesitic tuff and Ignimbrite.
4.2 Features
Host Rock for Lead
Always found as volcanic pipes over deep continental crust
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Data Not Available
Easter Island in the Polynesian Triangle, Pacific Ocean
4.3.3 Sculpture
4.3.4 Famous Sculptures
Data Not Available
Data Not Available
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 Formation
Picrite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
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.
5.2 Composition
5.2.1 Mineral Content
Biotite, Olivine, Plagioclase, Pyrrhotite
Calcite, Chlorite
5.2.2 Compound Content
Al, CaO, Carbon Dioxide, Mg, MgO
Hydrogen Sulfide, Sulfur Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Fine Grained
Fine Grained
6.1.3 Fracture
6.1.4 Streak
White, Greenish White or Grey
White
6.1.5 Porosity
Less Porous
Highly Porous
6.1.6 Luster
Subvitreous to Dull
Vitreous to Dull
6.1.7 Compressive Strength
189.00 N/mm2243.80 N/mm2
0.15
450
6.1.8 Cleavage
6.1.9 Toughness
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
1.5-2.5 g/cm31-1.8 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.88 kJ/Kg K0.20 kJ/Kg K
0.14
3.2
6.2.2 Resistance
Heat Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
India, Russia
Afghanistan, Armenia, Azerbaijan, Burma, Cambodia, China, India, Indonesia, Iran, Japan, Malaysia, Mongolia, Nepal, North Korea, Pakistan, Saudi Arabia, Syria, Taiwan, Thailand, Turkey, Vietnam, Yemen
7.1.2 Africa
South Africa
Cameroon, Cape Verde, Eritrea, Ethiopia, Kenya, Libya, Madagascar, Nigeria, Rwanda, South Africa, Sudan, Uganda
7.1.3 Europe
Iceland
France, Georgia, Germany, Greece, Iceland, Italy, Netherlands, Poland, Portugal, Spain, United Kingdom
7.1.4 Others
Not Yet Found
Antarctica, Hawaii Islands
7.2 Deposits in Western Continents
7.2.1 North America
Canada, USA
Canada, Costa Rica, Panama, USA
7.2.2 South America
Brazil
Argentina, Bolivia, Brazil, Chile, Ecuador, Paraguay
7.3 Deposits in Oceania Continent
7.3.1 Australia
Not Yet Found
Central Australia, Western Australia