Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Lherzolite is a type of ultramafic igneous rock which contains essential olivine and clinopyroxene and orthopyroxene in equal proportions
Origin
Romania and Moldova, Europe
France
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 the Lherz Massif, an alpine peridotite complex, at Étang de Lers, near Massat in the French Pyrenees; Lherz is the archaic spelling of this location
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
Fine Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Grenue
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Black, Dark Greenish - Grey, Green, Pink, Purple
Durability
Durable
Durable
Appearance
Vesicular
Glassy, Vesicular and Foilated
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Entryways, Homes, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Landscaping, Manufacture of Magnesium and Dolomite Refractories, Used for flooring, stair treads, borders and window sills.
Antiquity Uses
Artifacts
Artifacts, Sculpture
Commercial Uses
Commemorative Tablets, Creating Artwork
As armour rock for sea walls, Source of Magnesia (MgO), Used in aquariums
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Garnet Lherzolite
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.
Lherzolite 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.
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Harzburgite, Olivine, Pyroxene, Pyrrhotite
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
CaO, Cr, Chromium(III) Oxide, MgO
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Less Porous
Luster
Subvitreous to Dull
Subvitreous to Dull
Specific Gravity
2.86-2.87
2.86
Transparency
Translucent
Opaque
Density
2.77-2.771 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
Russia, South Korea
Europe
France, Greece, Romania, Scotland, Spain
United Kingdom
Deposits in Western Continents
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
-
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia
Central Australia, Western Australia