Definition
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
Rhyolite is a fine-grained igneous rock which is rich in silica
Origin
Unknown
North America
Discoverer
Unknown
Ferdinand von Richthofen
Etymology
From the mineral feldspathoid which is the main content of rock
From German Rhyolit, from Greek rhuax lava stream + lithos stone
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Earthy
Aphanitic, Glassy, Porphyritic
Color
Black, Brown, Colourless, Green, Grey, Pink, White
Grey, White, Light Black
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
Medical Industry
Taken as a Supplement for Calcium or Magnesium
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Gemstone, Laboratory bench tops, Jewelry
Types
Not Available
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Features
Host Rock for Lead
Acidic in nature, Available in lots of colors
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
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
Foidolites 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.
Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.
Mineral Content
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Not Applicable
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Large and Coarse Grained
Fracture
Conchoidal
Sub-conchoidal
Porosity
Very Less Porous
Highly Porous
Luster
Subvitreous to Dull
Earthy
Compressive Strength
Not Available
Cleavage
Perfect
Not Available
Toughness
Not Available
2
Specific Gravity
2.86
2.65-2.67
Transparency
Translucent
Opaque
Density
Not Available
2.4-2.6 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
South Africa, Western Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Not Yet Found
Germany, Iceland, Ireland, Italy, Spain
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Not Yet Found
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New Zealand, Queensland, Western Australia
All about Foidolite and Rhyolite Properties
Know all about Foidolite and Rhyolite properties here. All properties of rocks are important as they define the type of rock and its application. Foidolite and Rhyolite belong to Igneous Rocks.Texture of Foidolite is Earthy whereas that of Rhyolite is Aphanitic, Glassy, Porphyritic. Foidolite appears Dull and Rhyolite appears Banded. The luster of Foidolite is subvitreous to dull while that of Rhyolite is earthy. Foidolite is available in black, brown, colourless, green, grey, pink, white colors whereas Rhyolite is available in grey, white, light black colors. The commercial uses of Foidolite are cemetery markers, commemorative tablets, creating artwork and that of Rhyolite are gemstone, laboratory bench tops, jewelry.