Definition
Rhyolite is a fine-grained igneous rock which is rich in silica
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism
History
Origin
North America
England
Discoverer
Ferdinand von Richthofen
Abraham Gottlob Werner
Etymology
From German Rhyolit, from Greek rhuax lava stream + lithos stone
From Old French esclate, from esclat (French éclat)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Family
Group
Volcanic
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Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Aphanitic, Glassy, Porphyritic
Foliated
Color
Grey, White, Light Black
Black, Brown, Buff, Green, Light to Dark Grey, Purple, Red, Shades of Blue
Maintenance
More
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Banded
Dull
Architecture
Interior Uses
Decorative Aggregates, Homes, Hotels, Interior Decoration, Kitchens
Bathrooms, Decorative Aggregates, Entryways, Floor Tiles, Flooring, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
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
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Curbing
Industry
Construction Industry
Arrowheads, As Dimension Stone, Building houses or walls, Construction Aggregate, Cutting Tool, for Road Aggregate, Knives
As Dimension Stone
Medical Industry
-
-
Antiquity Uses
Artifacts
Artifacts, Monuments, Sculpture, Small Figurines
Other Uses
Commercial Uses
Gemstone, Laboratory bench tops, Jewelry
Blackboards, Commemorative Tablets, Laboratory bench tops, Standard material for the bed of Billiard table, Standard material for the beds of Pool and Snooker table, Tombstones, Used in aquariums, Writing Slates
Types
Pumice Rocks, Obsidian Rocks, Perlite Rocks, Porphyritic Rocks.
Phyllite, Schist, and Slate
Features
Acidic in nature, Available in lots of colors
Easily splits into thin plates, Surfaces are often shiny, Very fine grained 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.
Slate is a low grade metamorphic rock that is generally formed by metamorphosis of mudstone or shale, under relatively low pressure and temperature conditions.
Composition
Mineral Content
Biotite, Feldspar, Hornblade, Plagioclase, Pyroxene, Quartz
Apatite, Biotite, Chlorite, Feldspar, Graphite, Hematite, Kaolinite, Magnetite, Pyrite, Tourmaline, Zircon
Compound Content
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide, Sodium
Aluminium Oxide, CaO, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Regional Metamorphism
Burial Metamorphism, Cataclastic 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
Coastal Erosion, Glacier Erosion, Water Erosion, Wind Erosion
Physical Properties
Hardness
6-73-4
1
7
👆🏻
Grain Size
Large and Coarse Grained
Very fine-grained
Fracture
Sub-conchoidal
Splintery
Streak
-
Light to dark brown
Porosity
Highly Porous
Less Porous
Luster
Earthy
Dull
Compressive Strength
140.00 N/mm230.00 N/mm2
0.15
450
👆🏻
Cleavage
-
Slaty
Toughness
2
1.2
Specific Gravity
2.65-2.672.65-2.8
0
8.4
👆🏻
Transparency
Opaque
Opaque
Density
2.4-2.6 g/cm32.6-2.8 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.71 kJ/Kg K0.76 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, Turkey
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
-
Europe
Germany, Iceland, Ireland, Italy, Spain
Belgium, France, Germany, Italy, Norway, Portugal, Spain, United Kingdom
Others
-
Arctic
Deposits in Western Continents
North America
Canada, USA
USA
South America
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland, Western Australia
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