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.
  
History
  
  
Origin
North America
  
USA
  
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
  
Family
  
  
Group
Volcanic
  
Not Applicable
  
Other Categories
Coarse Grained Rock, Opaque Rock
  
Fine Grained Rock, Opaque Rock
  
Texture
Aphanitic, Glassy, Porphyritic
  
Quench
  
Color
Grey, White, Light Black
  
Black, Brown, Colourless, Green, Grey, Pink, White
  
Maintenance
More
  
Less
  
Durability
Durable
  
Durable
  
Water Resistant
Yes
  
Yes
  
Scratch Resistant
Yes
  
Yes
  
Stain Resistant
Yes
  
No
  
Wind Resistant
Yes
  
Yes
  
Acid Resistant
Yes
  
Yes
  
Appearance
Banded
  
Dull and Soft
  
Architecture
  
  
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
Not Yet Used
  
Curbing
  
Industry
  
  
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
  
Medical Industry
Not Yet Used
  
Not Yet Used
  
Antiquity Uses
Artifacts
  
Artifacts, Monuments
  
Other Uses
  
  
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
  
Creating Artwork, Gemstone
  
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
  
Not Available
  
Features
Acidic in nature, Available in lots of colors
  
Host Rock for Lead
  
Archaeological Significance
  
  
Monuments
Not Yet Used
  
Used
  
Famous Monuments
Not Applicable
  
Data Not Available
  
Sculpture
Not Yet Used
  
Not Yet Used
  
Famous Sculptures
Not Applicable
  
Not Applicable
  
Pictographs
Not Used
  
Not Used
  
Petroglyphs
Not Used
  
Not Used
  
Figurines
Not Yet Used
  
Not Yet Used
  
Fossils
Absent
  
Absent
  
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.
  
Composition
  
  
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
  
Transformation
  
  
Metamorphism
Yes
  
Yes
  
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
  
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism
  
Weathering
Yes
  
No
  
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
  
Not Applicable
  
Erosion
Yes
  
No
  
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
  
Not Applicable
  
Physical Properties
  
  
Hardness
6-7
  
7
  
Grain Size
Large and Coarse Grained
  
Very fine-grained
  
Fracture
Sub-conchoidal
  
Uneven
  
Streak
Colorless
  
Light to dark brown
  
Porosity
Highly Porous
  
Less Porous
  
Luster
Earthy
  
Vitreous
  
Compressive Strength
140.00 N/mm2
  
15
60.00 N/mm2
  
25
Cleavage
Not Available
  
Irregular
  
Toughness
2
  
Not Available
  
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
  
Thermal Properties
  
  
Specific Heat Capacity
Not Available
  
0.92 kJ/Kg K
  
10
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
  
Others
Not Yet Found
  
Not Yet Found
  
Deposits in Western Continents
  
  
North America
Canada, USA
  
Not Yet Found
  
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
  
Not Yet Found
  
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, colourless, 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 Not Available. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Rhyolite is colorless while that of Pseudotachylite is light to dark brown. The specific heat capacity of Rhyolite is Not Available 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.