Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
  
Rapakivi Granite is a hornblende-biotite Granite containing large rounded crystals of orthoclase which are mantled with oligoclase
  
History
  
  
Origin
USA
  
Finland, Europe
  
Discoverer
Unknown
  
Jakob Sederholm
  
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
  
From Finnish Rapakivi which stands for crumbly rock
  
Class
Metamorphic Rocks
  
Igneous Rocks
  
Sub-Class
Durable Rock, Hard Rock
  
Durable Rock, Hard Rock
  
Family
  
  
Group
Not Applicable
  
Plutonic
  
Other Categories
Fine Grained Rock, Opaque Rock
  
Coarse Grained Rock, Opaque Rock
  
Texture
Quench
  
Granular, Phaneritic
  
Color
Black, Brown, Colourless, Green, Grey, Pink, White
  
Black, Grey, Orange, Pink, White
  
Maintenance
Less
  
More
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
No
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull and Soft
  
Veined or Pebbled
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
  
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Office Buildings, Paving Stone, Resorts
  
Other Architectural Uses
Curbing
  
Not Yet Used
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
  
As Dimension Stone
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts, Monuments, Sculpture, Small Figurines
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone
  
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Laboratory bench tops, Tombstones
  
Types
Not Available
  
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
  
Features
Host Rock for Lead
  
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
  
Archaeological Significance
  
  
Monuments
Used
  
Used
  
Famous Monuments
Data Not Available
  
Data Not Available
  
Sculpture
Not Yet Used
  
Used
  
Famous Sculptures
Not Applicable
  
Data Not Available
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Not Yet Used
  
Used
  
Fossils
Absent
  
Absent
  
Formation
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
  
Granite is an igneous rock which is very hard, crystalline and is visibly homogeneous in texture and forms by melting of continental rocks
  
Composition
  
  
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
  
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
  
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
  
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
  
Physical Properties
  
  
Hardness
7
  
6-7
  
Grain Size
Very fine-grained
  
Large and Coarse Grained
  
Fracture
Uneven
  
Not Available
  
Streak
Light to dark brown
  
White
  
Porosity
Less Porous
  
Less Porous
  
Luster
Vitreous
  
Dull to Grainy with Sporadic parts Pearly and Vitreous
  
Compressive Strength
60.00 N/mm2
  
25
175.00 N/mm2
  
13
Cleavage
Irregular
  
Not Available
  
Toughness
Not Available
  
Not Available
  
Specific Gravity
2.46-2.86
  
2.6-2.7
  
Transparency
Transparent to Translucent
  
Opaque
  
Density
2.7-2.9 g/cm3
  
2.6-2.8 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
0.79 kJ/Kg K
  
16
Resistance
Heat Resistant
  
Heat Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
South Korea
  
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
  
Africa
Western Africa
  
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
  
Europe
Great Britain, Switzerland
  
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic, Venezuela
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Not Yet Found
  
Canada, USA
  
South America
Not Yet Found
  
Not Yet Found
  
Deposits in Oceania Continent
  
  
Australia
Central Australia, Western Australia
  
Not Yet Found
  
Pseudotachylite vs Rapakivi Granite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Pseudotachylite vs Rapakivi Granite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Pseudotachylite and Properties of Rapakivi Granite. Learn more about Pseudotachylite vs Rapakivi Granite in the next section. The interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration whereas the interior uses of Rapakivi Granite include Bathrooms, Countertops, Decorative aggregates, Entryways, Floor tiles, Flooring, Homes, Hotels, Interior decoration, Kitchens and Stair treads. Due to some exceptional properties of Pseudotachylite and Rapakivi Granite, they have various applications in construction industry. The uses of Pseudotachylite in construction industry include As dimension stone, Cement manufacture, For road aggregate, Making natural cement and that of Rapakivi Granite include As dimension stone.
More about Pseudotachylite and Rapakivi Granite
Here you can know more about Pseudotachylite and Rapakivi Granite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Pseudotachylite and Rapakivi Granite consists of mineral content and compound content. The mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides and mineral content of Rapakivi Granite includes Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz. You can also check out the list of all Metamorphic Rocks. When we have to compare Pseudotachylite vs Rapakivi Granite, the texture, color and appearance plays an important role in determining the type of rock. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas, Rapakivi Granite is available in black, grey, orange, pink, white colors. Appearance of Pseudotachylite is Dull and Soft and that of Rapakivi Granite is Veined or Pebbled. Properties of rock is another aspect for Pseudotachylite vs Rapakivi Granite. The hardness of Pseudotachylite is 7 and that of Rapakivi Granite is 6-7. The types of Pseudotachylite are Not Available whereas types of Rapakivi Granite are Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Pseudotachylite is light to dark brown while that of Rapakivi Granite is white. The specific heat capacity of Pseudotachylite is 0.92 kJ/Kg K and that of Rapakivi Granite is 0.79 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Pseudotachylite is heat resistant whereas Rapakivi Granite is heat resistant, wear resistant.