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
Rhyolite vs Pseudotachylite 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. Rhyolite vs Pseudotachylite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Rhyolite and Properties of Pseudotachylite. Learn more about Rhyolite vs Pseudotachylite in the next section. The interior uses of Rhyolite include Decorative aggregates, Homes, Hotels, Interior decoration and Kitchens whereas the interior uses of Pseudotachylite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Rhyolite and Pseudotachylite, they have various applications in construction industry. The uses of Rhyolite in construction industry include Arrowheads, As dimension stone, Building houses or walls, Construction aggregate, Cutting tool, For road aggregate, Knives and that of Pseudotachylite include As dimension stone, Cement manufacture, For road aggregate, Making natural cement.
More about Rhyolite and Pseudotachylite
Here you can know more about Rhyolite and Pseudotachylite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Rhyolite and Pseudotachylite consists of mineral content and compound content. The mineral content of Rhyolite includes Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz and mineral content of Pseudotachylite includes Iron Oxides, Pyroxene, Quartz, Stishovite, Sulfides. You can also check out the list of all Igneous Rocks. When we have to compare Rhyolite vs Pseudotachylite, the texture, color and appearance plays an important role in determining the type of rock. Rhyolite is available in grey, white, light black colors whereas, Pseudotachylite is available in black, brown, green, grey, pink, white colors. Appearance of Rhyolite is Banded and that of Pseudotachylite is Dull and Soft. Properties of rock is another aspect for Rhyolite vs Pseudotachylite. The hardness of Rhyolite is 6-7 and that of Pseudotachylite is 7. The types of Rhyolite are Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks. whereas types of Pseudotachylite are Cataclastic rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Rhyolite is while that of Pseudotachylite is light to dark brown. The specific heat capacity of Rhyolite is 0.71 kJ/Kg K and that of Pseudotachylite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Rhyolite is heat resistant, wear resistant whereas Pseudotachylite is heat resistant.