Definition
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Discoverer
Unknown
Unknown
Etymology
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Metamorphic Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Group
Not Applicable
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Quench
Clastic or Non-Clastic
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Grey, White, Yellow
Durability
Durable
Durable
Appearance
Dull and Soft
Soft
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, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Powder
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Making natural cement, raw material for manufacture of quicklime and slaked lime, Source of calcium
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone
Alumina Refineries, Creating Artwork, Drawing on blackboards, Gymnasts, athletes and mountain climbers use for grip, In aquifers, Paper Industry, Production of Lime, Raw material for manufacture of quicklime, slaked lime, Soil Conditioner, Whiting, Whiting material in toothpaste, paint and paper
Types
Not Available
Not Available
Features
Host Rock for Lead
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Famous Monuments
Data Not Available
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Used
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.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Mineral Content
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Ca, NaCl, CaO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Not Applicable
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Very fine-grained
Very fine-grained
Fracture
Uneven
Not Available
Streak
Light to dark brown
White
Porosity
Less Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Irregular
Non-Existent
Toughness
Not Available
1
Specific Gravity
2.46-2.86
2.3-2.4
Transparency
Transparent to Translucent
Opaque
Density
2.7-2.9 g/cm3
2.49-2.50 g/cm3
Resistance
Heat Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
South Korea
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
Western Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Great Britain, Switzerland
England, France, Germany, Spain, United Kingdom
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Not Yet Found
Canada, USA
South America
Not Yet Found
Colombia
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
Adelaide, New Zealand, Queensland, Tonga, Victoria, Yorke Peninsula
All about Pseudotachylite and Chalk Properties
Know all about Pseudotachylite and Chalk properties here. All properties of rocks are important as they define the type of rock and its application. Pseudotachylite belongs to Metamorphic Rocks while Chalk belongs to Sedimentary Rocks.Texture of Pseudotachylite is Quench whereas that of Chalk is Clastic or Non-Clastic. Pseudotachylite appears Dull and Soft and Chalk appears Soft. The luster of Pseudotachylite is vitreous while that of Chalk is dull. Pseudotachylite is available in black, brown, colourless, green, grey, pink, white colors whereas Chalk is available in grey, white, yellow colors. The commercial uses of Pseudotachylite are creating artwork, gemstone and that of Chalk are alumina refineries, creating artwork, drawing on blackboards, gymnasts, athletes and mountain climbers use for grip, in aquifers, paper industry, production of lime, raw material for manufacture of quicklime, slaked lime, soil conditioner, whiting, whiting material in toothpaste, paint and paper.