1 Definition
1.1 Definition
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Hornfels is a metamorphic rock formed by the contact between mudstone or other clay rich rock, and a hot igneous body, and represents a heat altered equivalent of the original rock
1.2 History
1.2.1 Origin
Romania and Moldova, Europe
New Zealand
1.2.2 Discoverer
1.3 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 which means hornstone
1.4 Class
Igneous Rocks
Metamorphic Rocks
1.4.1 Sub-Class
Durable Rock, Soft Rock
Durable Rock, Soft Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Aphanitic to Porphyritic
Granular, Platy
2.2 Color
Bluish - Grey, Brown, Grey, Light to Dark Grey
Brown, Dark Greenish - Grey, Green, Reddish Brown
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, Paving Stone, Garden Decoration
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
for Road Aggregate, Roadstone
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts
Artifacts, Monuments
3.4 Other Uses
3.4.1 Commercial Uses
Commemorative Tablets, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
4 Types
4.1 Types
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Biotite hornfels
4.2 Features
Host Rock for Lead, Is one of the oldest rock
Smooth to touch
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Not Applicable
Data Not Available
4.3.3 Sculpture
Not Yet Used
Not Yet Used
4.3.4 Famous Sculptures
Not Applicable
Not Applicable
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
Not Yet Used
Not Yet Used
4.4 Fossils
5 Formation
5.1 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. Hornfels is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
5.2 Composition
5.2.1 Mineral Content
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Andalusite
5.2.2 Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Fe, Mg
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism
Not Applicable
5.3.3 Weathering
5.3.4 Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Medium to Fine Coarse Grained
Fine Grained
6.1.3 Fracture
6.1.4 Streak
6.1.5 Porosity
Less Porous
Highly Porous
6.1.6 Luster
Subvitreous to Dull
Shiny
6.1.7 Compressive Strength
6.1.8 Cleavage
6.1.9 Toughness
Not Available
Not Yet Found
6.1.10 Specific Gravity
6.1.11 Transparency
6.1.12 Density
2.77-2.771 g/cm30.25-0.30 g/cm3
0
1400
6.2 Thermal Properties
6.2.1 Specific Heat Capacity
0.92 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
6.2.2 Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
7 Reserves
7.1 Deposits in Eastern Continents
7.1.1 Asia
Not Yet Found
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
7.1.2 Africa
Not Yet Found
Cameroon, East Africa, Tanzania, Western Africa
7.1.3 Europe
France, Greece, Romania, Scotland, Spain
United Kingdom
7.1.4 Others
Not Yet Found
Not Yet Found
7.2 Deposits in Western Continents
7.2.1 North America
7.2.2 South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Bolivia, Brazil, Colombia, Ecuador
7.3 Deposits in Oceania Continent
7.3.1 Australia
New Zealand, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Western Australia