Definition
Foidolite is a rare type of coarse-grained intrusive igneous rock with a feldspathoid mineral content greater than 60%
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Origin
-
Romania and Moldova, Europe
Discoverer
Unknown
Unknown
Etymology
From the mineral feldspathoid which is the main content of rock
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Earthy
Aphanitic to Porphyritic
Color
Black, Brown, Green, Grey, Pink, White
Bluish - Grey, Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull
Vesicular
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Commemorative Tablets, Creating Artwork
Types
Igneous rock
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Features
Host Rock for Lead
Host Rock for Lead, Is one of the oldest rock
Archaeological Significance
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.
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
Mineral Content
Amphibole, Biotite, Feldspar, Olivine, Plagioclase, Pyroxene
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
-
Chemical Erosion
Grain Size
Medium to Fine Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Specific Gravity
2.86
2.86-2.87
Transparency
Translucent
Translucent
Density
-9999 g/cm3
2.77-2.771 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
South Africa, Western Africa
-
Europe
-
France, Greece, Romania, Scotland, Spain
Deposits in Western Continents
North America
Canada, USA
USA
South America
-
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Central Australia, Western Australia
New Zealand, South Australia, Western Australia