Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
  
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
  
History
  
  
Origin
USA
  
Germany
  
Discoverer
Unknown
  
Christian Leopold von Buch
  
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
  
From Latin glaber bare, smooth, bald
  
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
  
Phaneritic
  
Color
Black, Brown, Colourless, Green, Grey, Pink, White
  
Dark Grey to Black
  
Maintenance
Less
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
No
  
Yes
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Dull and Soft
  
Veined and Shiny
  
Architecture
  
  
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
  
Countertops, Decorative Aggregates, Homes, Interior Decoration
  
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration
  
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
  
Other Architectural Uses
Curbing
  
Curbing
  
Industry
  
  
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
  
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts, Monuments
  
Artifacts, Monuments, Sculpture
  
Other Uses
  
  
Commercial Uses
Creating Artwork, Gemstone
  
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
  
Types
Not Available
  
Not Available
  
Features
Host Rock for Lead
  
Smooth to touch
  
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.
  
Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.
  
Composition
  
  
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
  
Augite, Olivine, Plagioclase, Pyroxene
  
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
  
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Impact Metamorphism
  
Weathering
No
  
Yes
  
Types of Weathering
Not Applicable
  
Chemical Weathering
  
Erosion
No
  
Yes
  
Types of Erosion
Not Applicable
  
Coastal Erosion
  
Physical Properties
  
  
Hardness
7
  
7
  
Grain Size
Very fine-grained
  
Coarse Grained
  
Fracture
Uneven
  
Conchoidal
  
Streak
Light to dark brown
  
Black
  
Porosity
Less Porous
  
Highly Porous
  
Luster
Vitreous
  
Not Available
  
Compressive Strength
60.00 N/mm2
  
25
225.00 N/mm2
  
7
Cleavage
Irregular
  
Not Available
  
Toughness
Not Available
  
1.6
  
Specific Gravity
2.46-2.86
  
2.86-2.87
  
Transparency
Transparent to Translucent
  
Opaque
  
Density
2.7-2.9 g/cm3
  
2.7-3.3 g/cm3
  
Thermal Properties
  
  
Specific Heat Capacity
0.92 kJ/Kg K
  
10
Not Available
  
Resistance
Heat Resistant
  
Impact Resistant, Pressure Resistant, Wear Resistant
  
Deposits in Eastern Continents
  
  
Asia
South Korea
  
India, Russia
  
Africa
Western Africa
  
South Africa
  
Europe
Great Britain, Switzerland
  
Germany, Greece, Italy, Scotland, Turkey
  
Others
Not Yet Found
  
Greenland
  
Deposits in Western Continents
  
  
North America
Not Yet Found
  
Canada, USA
  
South America
Not Yet Found
  
Brazil, Colombia, Venezuela
  
Deposits in Oceania Continent
  
  
Australia
Central Australia, Western Australia
  
New Zealand, Queensland