Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
History
Origin
Romania and Moldova, Europe
Discoverer
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
Class
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Family
Group
Volcanic
Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic to Porphyritic
Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Maintenance
Less
Durability
Durable
Water Resistant
✔
✘
81% - Igneous Rocks Rocks
Scratch Resistant
✔
✘
86% - Igneous Rocks Rocks
Stain Resistant
✔
✘
66% - Igneous Rocks Rocks
Wind Resistant
✔
✘
49% - Igneous Rocks Rocks
Acid Resistant
✔
✘
48% - Igneous Rocks Rocks
Appearance
Vesicular
Architecture
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Industry
Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Medical Industry
-
Antiquity Uses
Artifacts
Other Uses
Commercial Uses
Commemorative Tablets, Creating Artwork
Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Features
Host Rock for Lead, Is one of the oldest rock
Archaeological Significance
Monuments
-
Famous Monuments
-
Sculpture
-
Famous Sculptures
-
Pictographs
-
Petroglyphs
-
Figurines
-
Fossils
Absent
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.
Composition
Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Transformation
Metamorphism
✔
✘
97% - Igneous Rocks Rocks have it !
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Weathering
✔
✘
99% - Igneous Rocks Rocks have it !
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
92% - Igneous Rocks Rocks have it !
Types of Erosion
Chemical Erosion
Physical Properties
Hardness
2-2.25
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fracture
Conchoidal
Streak
White
Porosity
Less Porous
Luster
Subvitreous to Dull
Compressive Strength
70.00 N/mm2
Rank: 35 (Overall)
0.15
450
👆🏻
Cleavage
Perfect
Toughness
-
Specific Gravity
2.86-2.87
0
8.4
👆🏻
Transparency
Translucent
Density
2.77-2.771 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.92 kJ/Kg K
Rank: 10 (Overall)
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
-
Africa
-
Europe
France, Greece, Romania, Scotland, Spain
Others
-
Deposits in Western Continents
North America
USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, South Australia, Western Australia