Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Diabase is a fine-grained igneous rock which is composed mostly of pyroxene and feldspar
History
Origin
Iceland
Germany
Discoverer
Unknown
Christian Leopold von Buch
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
From Greek di + base
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Vitreous
Aphanitic, Granular
Color
Black, Dark Brown
Dark Grey to Black
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Glassy
Vesicular
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
An Oil and Gas Reservoir, Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Volcanic glass
Dolerite
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Smooth to touch
Archaeological Significance
Monuments
-
-
Famous Monuments
-
Stonehenge in English county of Wiltshire
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
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.
Diabase forms when molten igneous rock is squeezed up into a vertical crack in other rocks, the crack is usually forced apart and the molten rock cools in the space to form a tabular igneous intrusion cutting across the surrounding rocks and is known as a dike.
Composition
Mineral Content
Feldspar, Olivine
Augite, Chlorite, Olivine, Plagioclase, Pyroxene, Pyrrhotite, Serpentine
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Physical Properties
Hardness
5.57
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Fine to Medium Grained
Fracture
Conchoidal
Conchoidal
Streak
Vermilion
Black
Porosity
Less Porous
Highly Porous
Luster
Resinous
-
Compressive Strength
206.00 N/mm2225.00 N/mm2
0.15
450
👆🏻
Cleavage
-
-
Toughness
-
1.6
Specific Gravity
2.42.86-2.87
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
3.058 g/cm32.7-3.3 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.56 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Cambodia, Russia, South Korea
India
Africa
East Africa
South Africa, Tanzania
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
Germany, Greece, Italy, Scotland, Turkey
Others
Hawaii Islands
Antarctica, Greenland
Deposits in Western Continents
North America
USA
Canada, USA
South America
-
Argentina, Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Victoria
Central Australia, New Zealand, Queensland, Western Australia