Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Blueschist is a metamorphic rock which is generally blue in color and is formed under conditions of high pressure and low temperature
Discoverer
Ferdinand von Richthofen
Edgar Bailey
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From French schiste, Greek skhistos i.e. split
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Group
Volcanic
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Aphanitic, Glassy, Porphyritic
Foliated
Color
Grey, White, Light Black
Blue, Bluish - Grey, Purple, Shades of Blue
Durability
Durable
Durable
Appearance
Banded
Dull and Banded
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
Garden Decoration, Office Buildings
Other Architectural Uses
Not Yet Used
Not Yet Used
Construction Industry
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
Cemetery Markers, Commemorative Tablets, Creating Artwork, Curling, Tombstones
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Not Available
Features
Acidic in nature, Available in lots of colors
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
Not Yet Used
Used
Famous Monuments
Not Applicable
Data Not Available
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Used
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.
Blueschist forms due to the metamorphism of basalt and other rocks with similar composition at high pressures and low temperatures and approximately corresponding to a depth of 15 to 30 kilometers and 200 to 500 °C.
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Albite, Chlorite, Epidote, Garnet, Glaucophane, Lawsonite, Muscovite or Illite, Quartz
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Not Applicable
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Grain Size
Large and Coarse Grained
Fine to Medium Grained
Fracture
Sub-conchoidal
Conchoidal
Streak
Colorless
White to Grey
Porosity
Highly Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Not Available
Slaty
Specific Gravity
2.65-2.67
3-3.2
Transparency
Opaque
Opaque
Density
2.4-2.6 g/cm3
2.8-2.9 g/cm3
Resistance
Heat Resistant, Wear Resistant
Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India
Japan, Turkey
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Egypt, Ethiopia, South Africa
Europe
Germany, Iceland, Ireland, Italy, Spain
France, Greece, Iceland
Others
Not Yet Found
Not Yet Found
Deposits in Western Continents
North America
Canada, USA
USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Not Yet Found
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
New Zealand