Definition
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Pyroxenite is a dark, greenish, granular intrusive igneous rock consisting mainly of pyroxenes and olivine
Discoverer
Unknown
Unknown
Etymology
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
From pyro- fire + Greek xenos stranger as the mineral group was new to igneous rocks
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Clastic or Non-Clastic
Clastic, Granular, Phaneritic, Porphyritic
Color
Grey, White, Yellow
Black to Grey, Bluish - Grey, Dark Greenish - Grey, Green, Light Greenish Grey
Durability
Durable
Durable
Appearance
Soft
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Countertops, Decorative Aggregates, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone
Other Architectural Uses
Powder
Curbing
Construction Industry
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
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts
Commercial Uses
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
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Chalk Marl and Marl
Clinopyroxenites, Orthopyroxenites and Websterites
Features
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Generally rough to touch, Host rock for Diamond, Is one of the oldest rock
Archaeological Significance
Formation
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Pyroxenites are ultramafic igneous rocks which are made up of minerals of the pyroxene group, such as augite and diopside, hypersthene, bronzite or enstatite.
Mineral Content
Calcite, Clay, Clay Minerals, Quartz, Sand
Amphibole, Augite, Bronzite, Chromite, Diopside, Enstatite, Garnet, Hornblende, Hypersthene, Magnetite, Pyroxene
Compound Content
Ca, NaCl, CaO
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
-
Burial Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Very fine-grained
Coarse Grained
Streak
White
White, Greenish White or Grey
Porosity
Highly Porous
Less Porous
Luster
Dull
Dull to Vitreous to Submetallic
Specific Gravity
2.3-2.4
3.2-3.5
Transparency
Opaque
Opaque
Density
2.49-2.50 g/cm3
3.1-3.6 g/cm3
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
India, Russia
Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
South Africa
Europe
England, France, Germany, Spain, United Kingdom
Germany, Greece, Italy, Scotland, Turkey
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
New Zealand, Queensland
All about Chalk and Pyroxenite Properties
Know all about Chalk and Pyroxenite properties here. All properties of rocks are important as they define the type of rock and its application. Chalk belongs to Sedimentary Rocks while Pyroxenite belongs to Igneous Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Pyroxenite is Clastic, Granular, Phaneritic, Porphyritic. Chalk appears Soft and Pyroxenite appears Layered, Banded, Veined and Shiny. The luster of Chalk is dull while that of Pyroxenite is dull to vitreous to submetallic. Chalk is available in grey, white, yellow colors whereas Pyroxenite is available in black to grey, bluish - grey, dark greenish - grey, green, light greenish grey colors. The commercial uses 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 and that of Pyroxenite are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.