Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Adamellite is a coarse-grained porphyritic igneous rock, a variety of Monzogranite and dominated by phenocrysts of orthoclase in a granular groundmass of perthite, plagioclase and quartz
Origin
Romania and Moldova, Europe
Italy
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 German adamellit and from Monte Adamello, a mountain in Italy, its locality
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Porphyritic
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Grey, Orange, Pink, White
Durability
Durable
Durable
Appearance
Vesicular
Veined or Pebbled
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Homes, Hotels, Kitchens, Stair Treads
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Bridges, Paving Stone, Near Swimming Pools, Office Buildings, Resorts
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
As Dimension Stone
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Commemorative Tablets, Creating Artwork
Curling, Gemstone, Laboratory bench tops, Tombstones
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Granite
Features
Host Rock for Lead, Is one of the oldest rock
Available in Lots of Colors and Patterns, It is One of the Oldest, Strongest and Hardest Rock
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.
Adamellite is a type of Igneous rock which is formed through the cooling and solidification of lava or magma and is a variety of Monzogranite.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Apatite, Biotite, Chlorite, Orthoclase, Perthite, Plagioclase, Quartz, Titanite, Zircon
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Burial Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Glacier Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Coarse Grained
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Dull to Grainy with Sporadic parts Pearly and Vitreous
Specific Gravity
2.86-2.87
2.6-2.7
Transparency
Translucent
Opaque
Density
2.77-2.771 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
-
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
France, Greece, Romania, Scotland, Spain
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic
Deposits in Western Continents
North America
USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
-
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
-