Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Jadeitite is a metamorphic rock usually found in blueschist grade metamorphic terrains
Origin
Romania and Moldova, Europe
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Discoverer
Unknown
Unknown
Etymology
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
From pyroxene mineral jadeite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Earthy
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Appearance
Vesicular
Rough and Dull
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
As Dimension Stone, Cutting Tool, Knives
Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Commemorative Tablets, Creating Artwork
Commemorative Tablets, Creating Artwork, Jewelry
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Metamorphic rock
Features
Host Rock for Lead, Is one of the oldest rock
Host Rock for Lead
Archaeological Significance
Formation
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.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Jadeitite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Carbonate, Magnetite, Pyrrhotite, Serpentine, Sulfides
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Ca, CaO, Carbon Dioxide, KCl, MgO, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
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Types of Erosion
Chemical Erosion
Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Very fine-grained
Fracture
Conchoidal
Uneven
Streak
White
White, Greenish White or Grey
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Waxy and Dull
Specific Gravity
2.86-2.87
2.79-3
Transparency
Translucent
Opaque
Density
2.77-2.771 g/cm3
2.5-3 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Water Resistant
Deposits in Eastern Continents
Asia
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India, Saudi Arabia, Singapore, South Korea
Africa
-
Ethiopia, Western Africa
Europe
France, Greece, Romania, Scotland, Spain
England, Georgia, Switzerland, United Kingdom
Deposits in Western Continents
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, New South Wales, New Zealand, Western Australia