Definition
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
Trachyandesite is an extrusive igneous rock.
Origin
New Zealand
Indonesia
Discoverer
Unknown
Unknown
Etymology
From German which means hornstone
From French trachyandésite, trachy + andésite andesite, a lava intermediate in composition between trachyte and andesite
Class
Metamorphic Rocks
Igneous Rocks
Sub-Class
Durable Rock, Soft Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular, Platy
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Brown, Dark Greenish - Grey, Green, Reddish Brown
Black, Brown, Light to Dark Grey
Durability
Durable
Durable
Appearance
Dull
Dull and Soft
Interior Uses
Decorative Aggregates, Flooring, Homes, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
for Road Aggregate, Roadstone
Building houses or walls, Cobblestones, for Road Aggregate, Rail Track Ballast, Roadstone
Antiquity Uses
Artifacts, Monuments
Artifacts, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Creating Artwork
Creating Artwork, Pottery
Types
Biotite hornfels
Basaltic Trachyandesite
Features
Smooth to touch
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Formation
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.
Trachyandesite 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
Andalusite
Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
-
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Fine Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Streak
-
Light to dark brown
Porosity
Highly Porous
Less Porous
Specific Gravity
3.4-3.9
2.8-3
Transparency
Opaque
Opaque
Density
0.25-0.30 g/cm3
2.9-3.1 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
India, Russia
Africa
Cameroon, East Africa, Tanzania, Western Africa
South Africa
Europe
United Kingdom
Iceland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Bolivia, Brazil, Colombia, Ecuador
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, Western Australia
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Hornfels vs Trachyandesite Characteristics
Though some rocks look identical, they have certain characteristics which distinguish them from others. Characteristics of rocks include texture, appearance, color, fracture, streak, hardness etc. Hornfels vs Trachyandesite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Hornfels and Properties of Trachyandesite. Learn more about Hornfels vs Trachyandesite in the next section. The interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration whereas the interior uses of Trachyandesite include Countertops, Decorative aggregates, Homes and Interior decoration. Due to some exceptional properties of Hornfels and Trachyandesite, they have various applications in construction industry. The uses of Hornfels in construction industry include For road aggregate, Roadstone and that of Trachyandesite include Building houses or walls, Cobblestones, For road aggregate, Rail track ballast, Roadstone.
More about Hornfels and Trachyandesite
Here you can know more about Hornfels and Trachyandesite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Hornfels and Trachyandesite consists of mineral content and compound content. The mineral content of Hornfels includes Andalusite and mineral content of Trachyandesite includes Alkali feldspar, Biotite, Olivine, Plagioclase, Pyroxene, Sodic plagioclase. You can also check out the list of all Metamorphic Rocks. When we have to compare Hornfels vs Trachyandesite, the texture, color and appearance plays an important role in determining the type of rock. Hornfels is available in brown, dark greenish - grey, green, reddish brown colors whereas, Trachyandesite is available in black, brown, light to dark grey colors. Appearance of Hornfels is Dull and that of Trachyandesite is Dull and Soft. Properties of rock is another aspect for Hornfels vs Trachyandesite. The hardness of Hornfels is 2-3 and that of Trachyandesite is 4-5. The types of Hornfels are Biotite hornfels whereas types of Trachyandesite are Basaltic Trachyandesite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Hornfels is while that of Trachyandesite is light to dark brown. The specific heat capacity of Hornfels is 0.84 kJ/Kg K and that of Trachyandesite is 0.84 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Hornfels is heat resistant, impact resistant, pressure resistant whereas Trachyandesite is heat resistant, pressure resistant, wear resistant.