Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
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
Origin
Iceland
New Zealand
Discoverer
Unknown
Unknown
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
From German which means hornstone
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Vitreous
Granular, Platy
Color
Black, Dark Brown
Brown, Dark Greenish - Grey, Green, Reddish Brown
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
for Road Aggregate, Roadstone
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Creating Artwork
Cemetery Markers, Commemorative Tablets, Creating Artwork
Types
Volcanic glass
Biotite hornfels
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Smooth to touch
Archaeological Significance
Formation
Tachylite 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.
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.
Mineral Content
Feldspar, Olivine
Andalusite
Compound Content
Fe, Mg
Fe, Mg
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
-
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal
Porosity
Less Porous
Highly Porous
Specific Gravity
2.4
3.4-3.9
Transparency
Opaque
Opaque
Density
3.058 g/cm3
0.25-0.30 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
Cambodia, Russia, South Korea
Bangladesh, Bhutan, China, India, North Korea, Qatar, Russia, Saudi Arabia, South Korea, Thailand
Africa
East Africa
Cameroon, East Africa, Tanzania, Western Africa
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
United Kingdom
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Bolivia, Brazil, Colombia, Ecuador
Deposits in Oceania Continent
Australia
Victoria
New South Wales, New Zealand, Queensland, Western Australia
Tachylite vs Hornfels 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. Tachylite vs Hornfels characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Tachylite and Properties of Hornfels. Learn more about Tachylite vs Hornfels in the next section. The interior uses of Tachylite include Decorative aggregates and Interior decoration whereas the interior uses of Hornfels include Decorative aggregates, Flooring, Homes and Interior decoration. Due to some exceptional properties of Tachylite and Hornfels, they have various applications in construction industry. The uses of Tachylite in construction industry include Cutting tool, Knives, Landscaping, Scrapers and that of Hornfels include For road aggregate, Roadstone.
More about Tachylite and Hornfels
Here you can know more about Tachylite and Hornfels. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Tachylite and Hornfels consists of mineral content and compound content. The mineral content of Tachylite includes Feldspar, Olivine and mineral content of Hornfels includes Andalusite. You can also check out the list of all Igneous Rocks. When we have to compare Tachylite vs Hornfels, the texture, color and appearance plays an important role in determining the type of rock. Tachylite is available in black, dark brown colors whereas, Hornfels is available in brown, dark greenish - grey, green, reddish brown colors. Appearance of Tachylite is Glassy and that of Hornfels is Dull. Properties of rock is another aspect for Tachylite vs Hornfels. The hardness of Tachylite is 5.5 and that of Hornfels is 2-3. The types of Tachylite are Volcanic glass whereas types of Hornfels are Biotite hornfels. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Tachylite is vermilion while that of Hornfels is . The specific heat capacity of Tachylite is 0.56 kJ/Kg K and that of Hornfels 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.Tachylite is heat resistant, impact resistant, wear resistant whereas Hornfels is heat resistant, impact resistant, pressure resistant.