Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Felsite is a very fine grained volcanic rock that may or may not contain larger crystals and light colored rock that typically requires petrographic examination or chemical analysis for more precise definition
Discoverer
Unknown
Unknown
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From English feldspar and -ite
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Banded, Rough
Arborescent Patterned, Vitreous
Color
Black, Brown, Green, Grey, Red, White
Black, Blue, Brown, Green, Orange, Red, Tan, Yellow
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Glassy or Pearly
Layered, Banded, Veined and Shiny
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
Arrowheads, Cutting Tool, Knives, Scrapers, Spear Points
Medical Industry
-
Surgery
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Mirror, Jewelry
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Igneous rock
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Available in Lots of Colors and Patterns, Clasts are smooth to touch, Splintery, Very fine grained rock
Archaeological Significance
Formation
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.
Felsite is a fine-grained, hard rock which is a type of metasomatite, essentially altered basalt. It forms with or without crystallization, either below the surface as intrusive rocks or on the surface as extrusive rocks.
Mineral Content
Quartz, Silicon
Feldspar, Iron Oxides
Compound Content
Silicon Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
-
Burial Metamorphism, Contact Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Glacier Erosion, Water Erosion
Grain Size
Very fine-grained
Fine Grained
Fracture
Uneven, Splintery or Conchoidal
Conchoidal
Porosity
Highly Porous
Very Less Porous
Luster
Waxy and Dull
Vitreous
Specific Gravity
2.5-2.8
2.6-2.7
Transparency
Translucent to Opaque
Translucent
Density
2.7 g/cm3
2.6 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Afghanistan, Indonesia, Japan, Russia
Africa
Kenya, Morocco, South Africa, Tanzania
Kenya
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Greece, Hungary, Iceland, Italy, Turkey
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Mexico, USA
South America
Bolivia, Brazil
Argentina, Chile, Ecuador, Peru
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New Zealand
Chert vs Felsite 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. Chert vs Felsite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chert and Properties of Felsite. Learn more about Chert vs Felsite in the next section. The interior uses of Chert include Decorative aggregates and Homes whereas the interior uses of Felsite include Decorative aggregates, Flooring and Interior decoration. Due to some exceptional properties of Chert and Felsite, they have various applications in construction industry. The uses of Chert in construction industry include Arrowheads, Construction aggregate, Cutting tool, Spear points and that of Felsite include Arrowheads, Cutting tool, Knives, Scrapers, Spear points.
More about Chert and Felsite
Here you can know more about Chert and Felsite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chert and Felsite consists of mineral content and compound content. The mineral content of Chert includes Quartz, Silicon and mineral content of Felsite includes Feldspar, Iron Oxides. You can also check out the list of all Sedimentary Rocks. When we have to compare Chert vs Felsite, the texture, color and appearance plays an important role in determining the type of rock. Chert is available in black, brown, green, grey, red, white colors whereas, Felsite is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Chert is Glassy or Pearly and that of Felsite is Layered, Banded, Veined and Shiny. Properties of rock is another aspect for Chert vs Felsite. The hardness of Chert is 6.5-7 and that of Felsite is 5-5.5. The types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter whereas types of Felsite are Igneous rock. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chert and Felsite is white. The specific heat capacity of Chert is 0.74 kJ/Kg K and that of Felsite is 0.92 kJ/Kg K. Depending on the properties like hardness, toughness, specific heat capacity, porosity etc., rocks are resistant to heat, wear, impact, etc.Chert is heat resistant, impact resistant, pressure resistant, wear resistant whereas Felsite is heat resistant, impact resistant.