Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Very fine grained fault rock which is composed of glassy matrix that often contains inclusions of wall-rock fragments.
Discoverer
Ferdinand von Richthofen
Unknown
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From pseudo- + tachylite, a glassy rock generated by frictional heat within faults.
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic, Glassy, Porphyritic
Quench
Color
Grey, White, Light Black
Black, Brown, Green, Grey, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded
Dull and Soft
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration
Other Architectural Uses
-
Curbing
Construction Industry
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement
Antiquity Uses
Artifacts
Artifacts, Monuments
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
Creating Artwork, Gemstone
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Cataclastic rock
Features
Acidic in nature, Available in lots of colors
Host Rock for Lead
Archaeological Significance
Formation
Rhyolite is a felsic extrusive rock and due to its high silica content, rhyolite lava is very viscous and is volcanic equivalent of granite.
Due to change in environmental conditions, rocks are heated and pressurized deep inside the Earth's surface. Pseudotachylite is formed from the extreme heat caused by magma or by the intense collisions and friction of tectonic plates.
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Carbon Dioxide, Silicon Dioxide, Sulfur Dioxide, Sulphur
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
-
Grain Size
Large and Coarse Grained
Very fine-grained
Fracture
Sub-conchoidal
Uneven
Streak
-
Light to dark brown
Porosity
Highly Porous
Less Porous
Specific Gravity
2.65-2.67
2.46-2.86
Transparency
Opaque
Transparent to Translucent
Density
2.4-2.6 g/cm3
2.7-2.9 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Asia
China, India
South Korea
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Western Africa
Europe
Germany, Iceland, Ireland, Italy, Spain
Great Britain, Switzerland
Deposits in Western Continents
North America
Canada, USA
-
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
-
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
Central Australia, Western Australia
All about Rhyolite and Pseudotachylite Properties
Know all about Rhyolite and Pseudotachylite properties here. All properties of rocks are important as they define the type of rock and its application. Rhyolite belongs to Igneous Rocks while Pseudotachylite belongs to Metamorphic Rocks.Texture of Rhyolite is Aphanitic, Glassy, Porphyritic whereas that of Pseudotachylite is Quench. Rhyolite appears Banded and Pseudotachylite appears Dull and Soft. The luster of Rhyolite is earthy while that of Pseudotachylite is vitreous. Rhyolite is available in grey, white, light black colors whereas Pseudotachylite is available in black, brown, green, grey, pink, white colors. The commercial uses of Rhyolite are gemstone, laboratory bench tops, jewelry and that of Pseudotachylite are creating artwork, gemstone.