Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Quartzite is a non-foliated metamorphic rock that forms by the metamorphism of pure quartz Sandstone
History
Origin
North America
-
Discoverer
Ferdinand von Richthofen
Unknown
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From quartz + -ite
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Family
Group
Volcanic
-
Other Categories
Coarse Grained Rock, Opaque Rock
Medium Grained Rock, Opaque Rock
Texture
Aphanitic, Glassy, Porphyritic
Foliated, Granular
Color
Grey, White, Light Black
Black, Blue, Brown, Green, Light Grey, Purple, White, Yellow
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Banded
Lustrous
Architecture
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Countertops, Decorative Aggregates, Flooring, Homes
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
-
Curbing
Industry
Construction Industry
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
Arrowheads, As Dimension Stone, Cement Manufacture, Construction Aggregate, Cutting Tool, for Road Aggregate, Making natural cement, Production of Glass and Ceramics, Rail Track Ballast, Roadstone
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Jewellery, Monuments, Sculpture
Other Uses
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
An Oil and Gas Reservoir, As armour rock for sea walls, Cemetery Markers, Commemorative Tablets, In aquifers, Laboratory bench tops, Petroleum reservoirs, Soil Conditioner, Source of Magnesia (MgO), Tombstones, Used in aquariums
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Orthoquartzite and Metaquartzite
Features
Acidic in nature, Available in lots of colors
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
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.
Quartzite forms from sandstone and the mineral quartz being put under extreme heat and pressure.
Composition
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Chlorite, Epidote, Hematite, Kyanite, Magnetite, Muscovite or Illite, Quartz
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Aluminium Oxide, CaO, Iron(III) Oxide, MgO, Sodium Oxide, Silicon Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Hydrothermal Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Sea Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
6-76-7
1
7
👆🏻
Grain Size
Large and Coarse Grained
Medium Grained
Fracture
Sub-conchoidal
Uneven, Splintery or Conchoidal
Streak
-
White
Porosity
Highly Porous
Less Porous
Luster
Earthy
Vitreous
Compressive Strength
140.00 N/mm2115.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Indiscernible
Toughness
2
1.9
Specific Gravity
2.65-2.672.6-2.8
0
8.4
👆🏻
Transparency
Opaque
Transparent to Translucent
Density
2.4-2.6 g/cm32.32-2.42 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.71 kJ/Kg K0.75 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India
China, India, Israel, Russia, South Korea, Thailand, Turkey
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Ethiopia, Morocco, South Africa, Zimbabwe
Europe
Germany, Iceland, Ireland, Italy, Spain
England, Italy, Norway, Scotland, Sweden, United Kingdom
Others
-
Greenland
Deposits in Western Continents
North America
Canada, USA
Bahamas, Canada, USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
New Zealand, Queensland, Western Australia