Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Quartzite is a non-foliated metamorphic rock that forms by the metamorphism of pure quartz Sandstone
History
Origin
Iceland
-
Discoverer
Unknown
Unknown
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
From quartz + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Vitreous
Foliated, Granular
Color
Black, Dark Brown
Black, Blue, Brown, Green, Light Grey, Purple, White, Yellow
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Glassy
Lustrous
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
Arrowheads, As Dimension Stone, Cement Manufacture, Construction Aggregate, Cutting Tool, for Road Aggregate, Making natural cement, Production of Glass and Ceramics, Rail Track Ballast, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
Other Uses
Commercial Uses
Cemetery Markers, Creating Artwork
An Oil and Gas Reservoir, As armour rock for sea walls, Cemetery Markers, Commemorative Tablets, In aquifers, Laboratory bench tops, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones, Used in aquariums
Types
Volcanic glass
Orthoquartzite and Metaquartzite
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
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.
Quartzite forms from sandstone and the mineral quartz being put under extreme heat and pressure.
Composition
Mineral Content
Feldspar, Olivine
Chlorite, Epidote, Hematite, Kyanite, Magnetite, Muscovite or Illite, Quartz
Compound Content
Fe, Mg
Aluminium Oxide, CaO, Iron(III) Oxide, MgO, Sodium Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
5.56-7
1
7
👆🏻
Grain Size
Medium to Fine Coarse Grained
Medium Grained
Fracture
Conchoidal
Uneven, Splintery or Conchoidal
Streak
Vermilion
White
Porosity
Less Porous
Less Porous
Luster
Resinous
Vitreous
Compressive Strength
206.00 N/mm2115.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Indiscernible
Toughness
-
1.9
Specific Gravity
2.42.6-2.8
0
8.4
👆🏻
Transparency
Opaque
Transparent to Translucent
Density
3.058 g/cm32.32-2.42 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.56 kJ/Kg K0.75 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
China, India, Israel, Russia, South Korea, Thailand, Turkey
Africa
East Africa
Ethiopia, Morocco, South Africa, Zimbabwe
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
England, Italy, Norway, Scotland, Sweden, United Kingdom
Others
Hawaii Islands
Greenland
Deposits in Western Continents
North America
USA
Bahamas, Canada, USA
South America
-
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
Victoria
New Zealand, Queensland, Western Australia