Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Harzburgite is a plutonic rock of the peridotite group consisting largely of orthopyroxene and olivine
History
Origin
USA
Germany
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From the name of a town in Harzburg, Germany
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
-
Plutonic
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Quench
Phaneritic
Color
Black, Brown, Green, Grey, Pink, White
Dark Greenish - Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull and Soft
Rough and Shiny
Architecture
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
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, Cobblestones
Medical Industry
-
-
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Creating Artwork, Gemstone
Creating Artwork, Gemstone, Jewelry, Source of Chromite, Platinum, Nickel and Garnet, Source of Diamonds
Types
Cataclastic rock
Ultramafic rock
Features
Host Rock for Lead
Constitutes upper part of the Earth's mantle, Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
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.
Harzburgite 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.
Composition
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Amphibole, Chromite, Garnet, Magnesium, Olivine, Phlogopite, Plagioclase, Pyroxene
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Ca, Fe, Mg, Potassium, Silicon Dioxide, Sodium, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Impact Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
-
Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
-
Chemical Erosion, Sea Erosion
Physical Properties
Hardness
75.5-6
1
7
👆🏻
Grain Size
Very fine-grained
Coarse Grained
Fracture
Uneven
Irregular
Streak
Light to dark brown
White
Porosity
Less Porous
Less Porous
Luster
Vitreous
Shiny
Compressive Strength
60.00 N/mm2150.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
2.1
Specific Gravity
2.46-2.863-3.01
0
8.4
👆🏻
Transparency
Transparent to Translucent
Translucent to Opaque
Density
2.7-2.9 g/cm33.1-3.4 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K1.25 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
South Korea
Japan, Oman
Africa
Western Africa
South Africa
Europe
Great Britain, Switzerland
France, Germany, Italy
Others
-
Hawaii Islands, Mid-Atlantic Ridge
Deposits in Western Continents
North America
-
Canada, USA
South America
-
-
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
-