Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Greywacke is defined as a dark coarse-grained sandstone rock which contains more than 15 per cent clay
Origin
North America
Unknown
Discoverer
Ferdinand von Richthofen
Unknown
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From German Grauwacke, from grau grey + wacke
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Group
Volcanic
Not Applicable
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic, Glassy, Porphyritic
Clastic
Color
Grey, White, Light Black
Beige, Black, Brown, Colourless, Cream, Dark Brown, Green, Grey, Light Green, Light to Dark Grey, Pink, Red, White, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Decorative Aggregates, Floor Tiles, Flooring, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Not Yet Used
Curbing, Whetstones
Construction Industry
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Raw material for the manufacture of mortar
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts
Artifacts, Sculpture, Small Figurines
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
As armour rock for sea walls, Petroleum reservoirs, Sea Defence, Tombstones
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Not Available
Features
Acidic in nature, Available in lots of colors
Available in Lots of Colors and Patterns, Generally rough to touch, Non-vesicular, Veined
Archaeological Significance
Monuments
Not Yet Used
Not Yet Used
Famous Monuments
Not Applicable
Not Applicable
Sculpture
Not Yet Used
Used
Famous Sculptures
Not Applicable
Data Not Available
Pictographs
Not Used
Not Used
Petroglyphs
Not Used
Not 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.
Graywacke rock is a type of sedimentary rock, which is also known as immature sandstone, which is indurated, dark grey and consisting of poorly sorted angular to sub-angular, sand-sized grains.
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Augite, Biotite, Calcite, Chlorite, Clay, Clay Minerals, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Aluminium Oxide, NaCl, CaO, Chromium(III) Oxide, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, 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
Biological Weathering, Chemical Weathering
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Coastal Erosion, Sea Erosion, Wind Erosion
Grain Size
Large and Coarse Grained
Angular and Fine
Fracture
Sub-conchoidal
Conchoidal
Porosity
Highly Porous
Highly Porous
Compressive Strength
Not Available
Cleavage
Not Available
Perfect
Specific Gravity
2.65-2.67
2.2-2.8
Transparency
Opaque
Opaque
Density
2.4-2.6 g/cm3
2.6-2.61 g/cm3
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant
Deposits in Eastern Continents
Asia
China, India
China, India, Kazakhstan, Mongolia, Russia, Uzbekistan
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Namibia, Nigeria, South Africa
Europe
Germany, Iceland, Ireland, Italy, Spain
Austria, Denmark, Germany, Great Britain, Netherlands, Norway, Poland, Sweden, Switzerland, United Kingdom
Others
Not Yet Found
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
New South Wales, New Zealand
All about Rhyolite and Greywacke Properties
Know all about Rhyolite and Greywacke properties here. All properties of rocks are important as they define the type of rock and its application. Rhyolite belongs to Igneous Rocks while Greywacke belongs to Sedimentary Rocks.Texture of Rhyolite is Aphanitic, Glassy, Porphyritic whereas that of Greywacke is Clastic. Rhyolite appears Banded and Greywacke appears Dull. The luster of Rhyolite is earthy while that of Greywacke is dull. Rhyolite is available in grey, white, light black colors whereas Greywacke is available in beige, black, brown, colourless, cream, dark brown, green, grey, light green, light to dark grey, pink, red, white, yellow colors. The commercial uses of Rhyolite are gemstone, laboratory bench tops, jewelry and that of Greywacke are as armour rock for sea walls, petroleum reservoirs, sea defence, tombstones.