Definition
Phonolite is an uncommon extrusive igneous rock volcanic rock of intermediate chemical composition between felsic and mafic
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Discoverer
Unknown
Unknown
Etymology
From the Greek meaning sounding stone because of the metallic sound it produces if an unfractured plate is hit
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Granular
Banded, Rough
Color
Brown, Buff, Cream, Green, Grey, Pink, White
Black, Brown, Green, Grey, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Banded and Foilated
Glassy or Pearly
Interior Uses
Countertops, Decorative Aggregates, Flooring, Homes
Decorative Aggregates, Homes
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories, Production of Glass and Ceramics
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments
Commercial Uses
Cemetery Markers, Creating Artwork
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Types
Kenyte
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Features
Application of acids on the surface causes cloudy frosting, Available in Lots of Colors and Patterns, Dissolves in hydrochloric acid, Is one of the oldest rock
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Archaeological Significance
Formation
Phonolite are formed due to alkaline igneous activities and are generally formed in thick continental crustal areas or in Cordilleran subduction zones.
Chert forms when microcrystals of silicon dioxide grow within soft sediments that become limestone or chalk. The chert formation can be either of chemical or biological origin.
Mineral Content
Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite
Quartz, Silicon
Compound Content
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Silicon Dioxide
Types of Metamorphism
Contact Metamorphism
-
Types of Weathering
Chemical Weathering, Mechanical Weathering
-
Types of Erosion
Chemical Erosion, Coastal Erosion, Water Erosion, Wind Erosion
Chemical Erosion
Grain Size
Fine Grained
Very fine-grained
Fracture
Conchoidal to Uneven
Uneven, Splintery or Conchoidal
Porosity
Less Porous
Highly Porous
Luster
Greasy to Dull
Waxy and Dull
Specific Gravity
2.6
2.5-2.8
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.6 g/cm3
2.7 g/cm3
Resistance
Heat Resistant, Impact Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Indonesia, Iran, Russia, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Turkmenistan, Vietnam
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Africa
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Kenya, Morocco, South Africa, Tanzania
Europe
Andorra, Finland, France, Germany, Great Britain, Italy, Norway, Portugal, Spain, Sweden
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Others
Greenland
Greenland, Mid-Atlantic Ridge
Deposits in Western Continents
North America
Canada, USA
Canada, Mexico, USA
South America
Brazil, Chile, Colombia, Uruguay, Venezuela
Bolivia, Brazil
Deposits in Oceania Continent
Australia
New Zealand, Queensland, South Australia, Tasmania, Western Australia
New South Wales, Queensland, South Australia, Western Australia
Phonolite vs Chert 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. Phonolite vs Chert characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Phonolite and Properties of Chert. Learn more about Phonolite vs Chert in the next section. The interior uses of Phonolite include Countertops, Decorative aggregates, Flooring and Homes whereas the interior uses of Chert include Decorative aggregates and Homes. Due to some exceptional properties of Phonolite and Chert, they have various applications in construction industry. The uses of Phonolite in construction industry include As dimension stone, Cement manufacture, Construction aggregate, For road aggregate, Landscaping, Making natural cement, Manufacture of magnesium and dolomite refractories, Production of glass and ceramics and that of Chert include Arrowheads, Construction aggregate, Cutting tool, Spear points.
More about Phonolite and Chert
Here you can know more about Phonolite and Chert. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Phonolite and Chert consists of mineral content and compound content. The mineral content of Phonolite includes Albite, Amphibole, Biotite, Cancrinite, Feldspar, Hornblende, Plagioclase, Pyroxene, Sodalite and mineral content of Chert includes Quartz, Silicon. You can also check out the list of all Igneous Rocks. When we have to compare Phonolite vs Chert, the texture, color and appearance plays an important role in determining the type of rock. Phonolite is available in brown, buff, cream, green, grey, pink, white colors whereas, Chert is available in black, brown, green, grey, red, white colors. Appearance of Phonolite is Banded and Foilated and that of Chert is Glassy or Pearly. Properties of rock is another aspect for Phonolite vs Chert. The hardness of Phonolite is 5.5-6 and that of Chert is 6.5-7. The types of Phonolite are Kenyte whereas types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Phonolite and Chert is white. The specific heat capacity of Phonolite is 0.84 kJ/Kg K and that of Chert is 0.74 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Phonolite is heat resistant, impact resistant, wear resistant whereas Chert is heat resistant, impact resistant, pressure resistant, wear resistant.