Definition
Teschenite is coarse- to fine-grained, dark-coloured intrusive igneous rock that usually occurs in sills, dikes and irregular masses and is always altered to some extent
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Origin
Scotland
Romania and Moldova, Europe
Discoverer
Unknown
Unknown
Etymology
From its occurrence near Teschen. now known as Cieszyn, Pol., Scotland
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, Hard Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Phaneritic
Aphanitic to Porphyritic
Color
Dark Grey to Black
Bluish - Grey, Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Veined and Shiny
Vesicular
Interior Uses
Countertops, Decorative Aggregates, Entryways, Homes, Interior Decoration
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
As Building Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Antiquity Uses
Artifacts, Sculpture
Artifacts
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Commemorative Tablets, Creating Artwork
Types
Igneous rock
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Features
Smooth to touch
Host Rock for Lead, Is one of the oldest rock
Archaeological Significance
Formation
Teschenite 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
Augite, Olivine, Plagioclase, Pyroxene
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Coarse Grained
Medium to Fine Coarse Grained
Fracture
Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
-
Subvitreous to Dull
Specific Gravity
2.86-2.87
2.86-2.87
Transparency
Opaque
Translucent
Density
2.7-3.3 g/cm3
2.77-2.771 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Europe
Germany, Greece, Italy, Scotland, Turkey
France, Greece, Romania, Scotland, Spain
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil, Colombia, Venezuela
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New Zealand, South Australia, Western Australia