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
Rhyodacite is an extrusive volcanic rock intermediate in composition between dacite and rhyolite
Discoverer
Georgius Agricola
Unknown
Etymology
From Late Latin Basaltes (variant of basanites ), very hard stone, which was imported from Ancient Greek Basanites
Rhyo lite + dacite : a rock intermediate between rhyolite and dacite that is the extrusive equivalent of granodiorite
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Earthy
Color
Black, Brown, Light to Dark Grey
Black to Grey, Dark Greenish - Grey
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull and Soft
Skeletal
Interior Uses
Floor Tiles, Homes, Hotels, Kitchens
Decorative Aggregates, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, Garden Decoration
Other Architectural Uses
Curbing, Whetstones
Curbing
Construction Industry
Arrowheads, As Dimension Stone, Cobblestones, Cutting Tool, Rail Track Ballast, Roadstone
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
An Oil and Gas Reservoir, Commemorative Tablets, Creating Artwork, Used in aquariums
Cemetery Markers, Creating Artwork
Types
Alkaline Basalt, Boninite, High Alumina Basalt, Mid Ocean Ridge Basalt (MORB), Tholeiitic Basalt, Basaltic trachyandesite, Mugearite and Shoshonite
Not Available
Features
Has High structural resistance against erosion and climate, Very fine grained rock
Available in Lots of Colors and Patterns
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Easter Island in the Polynesian Triangle, Pacific Ocean, Gateway of India in Mumbai, India, Gol Gumbaz in Karnataka, India
Not Applicable
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
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.
Rhyodacite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Olivine, Plagioclase, Pyroxene
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Ca, Fe, Potassium Oxide, NA, Potassium, Silicon Dioxide
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Available
Chemical Erosion, Coastal Erosion, Glacier Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
White to Grey
Black
Porosity
Less Porous
Less Porous
Luster
Not Available
Greasy to Dull
Cleavage
Not Available
Not Available
Specific Gravity
2.8-3
2.34-2.40
Transparency
Opaque
Opaque
Density
2.9-3.1 g/cm3
Not Available
Resistance
Heat Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
India, Russia
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
South Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Iceland
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil
Not Yet Found
Deposits in Oceania Continent
Australia
Not Yet Found
Not Yet Found
Basalt vs Rhyodacite 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 Rhyodacite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Basalt and Properties of Rhyodacite. Learn more about Basalt vs Rhyodacite in the next section. The interior uses of Basalt include Floor tiles, Homes, Hotels and Kitchens whereas the interior uses of Rhyodacite include Decorative aggregates and Interior decoration. Due to some exceptional properties of Basalt and Rhyodacite, 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 Rhyodacite include As dimension stone, Construction aggregate, For road aggregate, Landscaping.
More about Basalt and Rhyodacite
Here you can know more about Basalt and Rhyodacite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Basalt and Rhyodacite consists of mineral content and compound content. The mineral content of Basalt includes Olivine, Plagioclase, Pyroxene and mineral content of Rhyodacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon. You can also check out the list of all Igneous Rocks. When we have to compare Basalt vs Rhyodacite, 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, Rhyodacite is available in black to grey, dark greenish - grey colors. Appearance of Basalt is Dull and Soft and that of Rhyodacite is Skeletal. Properties of rock is another aspect for Basalt vs Rhyodacite. The hardness of Basalt is 6 and that of Rhyodacite is 5.5-6. 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 Rhyodacite are Not Available. 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 Rhyodacite is black. The specific heat capacity of Basalt is 0.84 kJ/Kg K and that of Rhyodacite is 1.12 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 Rhyodacite is heat resistant.