Definition
Basalt is a common extrusive igneous rock formed by the rapid cooling of basaltic lava exposed at or very near the surface of Earth
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Discoverer
Georgius Agricola
Unknown
Etymology
From Late Latin Basaltes (variant of basanites ), very hard stone, which was imported from Ancient Greek Basanites
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Banded, Rough
Color
Black, Brown, Light to Dark Grey
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Glassy or Pearly
Interior Uses
Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
Arrowheads, As Dimension Stone, Cobblestones, Cutting Tool, Rail Track Ballast, Roadstone
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments
Commercial Uses
An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork, Used in aquariums
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean, Gateway of India in Mumbai, India, Gol Gumbaz in Karnataka, India
Data Not Available
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Not Yet Used
Formation
Basalt forms when lava reaches the Earth's surface near an active volcano. The temperature of lava is between 1100 to 1250° C when it gets to the surface.
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.
Mineral Content
Olivine, Plagioclase, Pyroxene
Quartz, Silicon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Types of Metamorphism
Contact Metamorphism
Not Applicable
Types of Weathering
Biological Weathering
Not Applicable
Types of Erosion
Not Available
Chemical Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Streak
White to Grey
White
Porosity
Less Porous
Highly Porous
Luster
Not Available
Waxy and Dull
Cleavage
Not Available
Non-Existent
Specific Gravity
2.8-3
2.5-2.8
Transparency
Opaque
Translucent to Opaque
Density
2.9-3.1 g/cm3
2.7 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Iceland
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Not Yet Found
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil
Bolivia, Brazil
Deposits in Oceania Continent
Australia
Not Yet Found
New South Wales, Queensland, South Australia, Western Australia
Basalt vs Chert 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. Basalt vs Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Basalt and Properties of Chert. Learn more about Basalt vs Chert in the next section. The interior uses of Basalt include Floor tiles, Homes, Hotels and Kitchens whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Basalt and Chert, they have various applications in construction industry. The uses of Basalt in construction industry include Arrowheads, As dimension stone, Cobblestones, Cutting tool, Rail track ballast, Roadstone and that of Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Basalt and Chert
Here you can know more about Basalt and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Basalt and Chert consists of mineral content and compound content. The mineral content of Basalt includes Olivine, Plagioclase, Pyroxene and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Igneous Rocks. When we have to compare Basalt vs Chert, the texture, color and appearance plays an important role in determining the type of rock. Basalt is available in black, brown, light to dark grey colors whereas, Chert is available in black, brown, green, grey, red, white colors. Appearance of Basalt is Dull and Soft and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Basalt vs Chert. The hardness of Basalt is 6 and that of Chert is 6.5-7. The types of Basalt are Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite whereas types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Basalt is white to grey while that of Chert is white. The specific heat capacity of Basalt is 0.84 kJ/Kg K and that of Chert is 0.74 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Basalt is heat resistant, pressure resistant, wear resistant whereas Chert is heat resistant, impact resistant, pressure resistant, wear resistant.