Definition
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Chalk is a soft, white, powdery limestone consisting mainly of fossil shells of foraminifers
Discoverer
R. J. Hauy
Unknown
Etymology
From Greek pegma, pegmat which means- thing joined together + -ite
From old English cealc chalk, lime, plaster; pebble, from Greek khalix small pebble, in English transferred to the opaque, white, soft limestone
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Pegmatitic
Clastic or Non-Clastic
Color
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Grey, White, Yellow
Durability
Durable
Durable
Appearance
Layered, Banded, Veined and Shiny
Soft
Interior Uses
Decorative Aggregates, Flooring, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Powder
Construction Industry
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
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
Antiquity Uses
Artifacts, Sculpture, Small Figurines
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
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
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Chalk Marl and Marl
Features
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Clasts are smooth to touch, Is one of the oldest rock, Smooth to touch, Very fine grained rock
Archaeological Significance
Formation
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Chalk is formed from lime mud, which accumulates on the sea floor which is then transformed into rock by geological processes.
Mineral Content
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Calcite, Clay, Clay Minerals, Quartz, Sand
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Ca, NaCl, CaO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
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Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Medium to Coarse Grained
Very fine-grained
Porosity
Less Porous
Highly Porous
Luster
Grainy, Pearly and Vitreous
Dull
Specific Gravity
2.6-2.63
2.3-2.4
Transparency
Translucent to Opaque
Opaque
Density
2.6-2.65 g/cm3
2.49-2.50 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Brunei, India, Indonesia, Malaysia, Singapore, Thailand, Vietnam
Africa
South Africa
Cameroon, Chad, Ghana, Kenya, Malawi, Sudan, Tanzania, Togo, Zambia, Zimbabwe
Europe
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
England, France, Germany, Spain, United Kingdom
Deposits in Western Continents
North America
Canada
Canada, USA
South America
Brazil
Colombia
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
Adelaide, New Zealand, Queensland, Victoria, Yorke Peninsula
All about Pegmatite and Chalk Properties
Know all about Pegmatite and Chalk properties here. All properties of rocks are important as they define the type of rock and its application. Pegmatite belongs to Igneous Rocks while Chalk belongs to Sedimentary Rocks.Texture of Pegmatite is Pegmatitic whereas that of Chalk is Clastic or Non-Clastic. Pegmatite appears Layered, Banded, Veined and Shiny and Chalk appears Soft. The luster of Pegmatite is grainy, pearly and vitreous while that of Chalk is dull. Pegmatite and Chalk are available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. The commercial uses of Pegmatite are creating artwork, jewelry, source of corundum, tourmalines, beryls and topaz 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.