Definition
Tachylite is a vitreous form of basaltic volcanic glass. This glass is formed naturally by the rapid cooling of molten basalt
Rhyolite is a fine-grained igneous rock which is rich in silica
Origin
Iceland
North America
Discoverer
Unknown
Ferdinand von Richthofen
Etymology
From German Tachylite, from tachy- + Greek lutos soluble, melting
From German Rhyolit, from Greek rhuax lava stream + lithos stone
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Fine Grained Rock, Medium Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Vitreous
Aphanitic, Glassy, Porphyritic
Color
Black, Dark Brown
Grey, White, Light Black
Durability
Durable
Durable
Interior Uses
Decorative Aggregates, Interior Decoration
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Other Architectural Uses
Curbing
Not Yet Used
Construction Industry
Cutting Tool, Knives, Landscaping, Scrapers
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts
Commercial Uses
Cemetery Markers, Creating Artwork
Gemstone, Laboratory bench tops, Jewelry
Types
Not Available
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Features
Available in Lots of Colors and Patterns, Clasts are smooth to touch, NA
Acidic in nature, Available in lots of colors
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Not Yet Used
Not Yet Used
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.
Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.
Mineral Content
Feldspar, Olivine
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Compound Content
Fe, Mg
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Grain Size
Medium to Fine Coarse Grained
Large and Coarse Grained
Fracture
Conchoidal
Sub-conchoidal
Streak
Vermilion
Colorless
Porosity
Less Porous
Highly Porous
Cleavage
Not Available
Not Available
Toughness
Not Available
2
Specific Gravity
2.4
2.65-2.67
Transparency
Opaque
Opaque
Density
3.058 g/cm3
2.4-2.6 g/cm3
Specific Heat Capacity
Not Available
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Cambodia, Russia, South Korea
China, India
Africa
East Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
England, Germany, Hungary, Iceland, Scotland, Sweden
Germany, Iceland, Ireland, Italy, Spain
Others
Hawaii Islands
Not Yet Found
Deposits in Western Continents
North America
USA
Canada, USA
South America
Not Yet Found
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
Victoria
New Zealand, Queensland, Western Australia