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
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
Discoverer
Georgius Agricola
Unknown
Etymology
From Late Latin Basaltes (variant of basanites ), very hard stone, which was imported from Ancient Greek Basanites
From German which means hornstone
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Granular, Platy
Color
Black, Brown, Light to Dark Grey
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Appearance
Dull and Soft
Dull
Interior Uses
Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
Arrowheads, As Dimension Stone, Cobblestones, Cutting Tool, Rail Track Ballast, Roadstone
for Road Aggregate, Roadstone
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments
Commercial Uses
An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork, Used in aquariums
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Biotite hornfels
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Smooth to touch
Archaeological Significance
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean, Gateway of India in Mumbai, India, Gol Gumbaz in Karnataka, India
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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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Olivine, Plagioclase, Pyroxene
Andalusite
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Fe, Mg
Types of Metamorphism
Contact Metamorphism
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Types of Weathering
Biological Weathering
Biological Weathering
Types of Erosion
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Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Highly Porous
Specific Gravity
2.8-3
3.4-3.9
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
India, Russia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
South Africa
Cameroon, East Africa, Tanzania, Western Africa
Europe
Iceland
United Kingdom
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
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New South Wales, New Zealand, Queensland, Western Australia
All about Basalt and Hornfels Properties
Know all about Basalt and Hornfels properties here. All properties of rocks are important as they define the type of rock and its application. Basalt belongs to Igneous Rocks while Hornfels belongs to Metamorphic Rocks.Texture of Basalt is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Hornfels is Granular, Platy. Basalt appears Dull and Soft and Hornfels appears Dull. The luster of Basalt is while that of Hornfels is shiny. Basalt is available in black, brown, light to dark grey colors whereas Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. The commercial uses of Basalt are an oil and gas reservoir, commemorative tablets, creating artwork, used in aquariums and that of Hornfels are cemetery markers, commemorative tablets, creating artwork.