Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Pegmatite rock is a holocrystalline, intrusive igneous rock which is composed of interlocking phaneritic crystals
Discoverer
Unknown
R. J. Hauy
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From Greek pegma, pegmat which means- thing joined together + -ite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Banded, Rough
Pegmatitic
Color
Black, Brown, Green, Grey, Red, White
Black, Brown, Cream, Green, Grey, Pink, Red, Rust, Silver, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Glassy or Pearly
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
As Dimension Stone, Building houses or walls, Construction Aggregate, for Road Aggregate, Landscaping
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture, Small Figurines
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Creating Artwork, Jewelry, Source of corundum, tourmalines, beryls and topaz
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Generally rough to touch, Is one of the oldest rock, Source of corundum, tourmalines, beryls and topaz
Archaeological Significance
Formation
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Pegmatite rock is holocrystalline, intrusive igneous rock which is formed by partial melting and dewatering during the process of metamorphism.
Mineral Content
Quartz, Silicon
Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz
Compound Content
Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, Phosphorus Pentoxide
Types of Metamorphism
-
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Medium to Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Waxy and Dull
Grainy, Pearly and Vitreous
Specific Gravity
2.5-2.8
2.6-2.63
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.7 g/cm3
2.6-2.65 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Iran, Japan, Nepal, North Korea, Russia, Saudi Arabia, South Korea
Africa
Kenya, Morocco, South Africa, Tanzania
South Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Austria, France, Greece, Ireland, Italy, Netherlands, Slovakia, Spain, Turkey, Ukraine
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada
South America
Bolivia, Brazil
Brazil
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New South Wales, Queensland, South Australia, Western Australia
Chert vs Pegmatite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Chert vs Pegmatite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chert and Properties of Pegmatite. Learn more about Chert vs Pegmatite in the next section. The interior uses of Chert include Decorative aggregates and Homes whereas the interior uses of Pegmatite include Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Chert and Pegmatite, they have various applications in construction industry. The uses of Chert in construction industry include Arrowheads, Construction aggregate, Cutting tool, Spear points and that of Pegmatite include As dimension stone, Building houses or walls, Construction aggregate, For road aggregate, Landscaping.
More about Chert and Pegmatite
Here you can know more about Chert and Pegmatite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chert and Pegmatite consists of mineral content and compound content. The mineral content of Chert includes Quartz, Silicon and mineral content of Pegmatite includes Apatite, Beryl, Feldspar, Fluorite, Garnet, Lepidolite, Quartz, Silica, Spodumene, Topaz. You can also check out the list of all Sedimentary Rocks. When we have to compare Chert vs Pegmatite, the texture, color and appearance plays an important role in determining the type of rock. Chert is available in black, brown, green, grey, red, white colors whereas, Pegmatite is available in black, brown, cream, green, grey, pink, red, rust, silver, white, yellow colors. Appearance of Chert is Glassy or Pearly and that of Pegmatite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Chert vs Pegmatite. The hardness of Chert is 6.5-7 and that of Pegmatite is 7. The types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter whereas types of Pegmatite are Granite Pegmatite, Gabbro Pegmatite and Diorite Pegmatite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chert and Pegmatite is white. The specific heat capacity of Chert is 0.74 kJ/Kg K and that of Pegmatite is 0.79 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Chert is heat resistant, impact resistant, pressure resistant, wear resistant whereas Pegmatite is heat resistant, impact resistant, pressure resistant.