Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Dacite is a volcanic igneous rock which is rintermediate in composition between andesite and rhyolite
Origin
Unknown
Romania and Moldova, Europe
Discoverer
Unknown
Unknown
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From Dacia, a province of the Roman Empire which lay between the Danube River and Carpathian Mountains where the rock was first described
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Group
Not Applicable
Volcanic
Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Banded, Rough
Aphanitic to Porphyritic
Color
Black, Brown, Green, Grey, Red, White
Bluish - Grey, Brown, Grey, Light to Dark Grey
Durability
Durable
Durable
Appearance
Glassy or Pearly
Vesicular
Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Entryways, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, Paving Stone, Garden Decoration
Other Architectural Uses
Curbing
Curbing
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
As Dimension Stone, Construction Aggregate, for Road Aggregate, Landscaping
Medical Industry
Not Yet Used
Not Yet Used
Antiquity Uses
Artifacts, Monuments
Artifacts
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Commemorative Tablets, Creating Artwork
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite
Features
Clasts are smooth to touch, Easily splits into thin plates, Has High structural resistance against erosion and climate
Host Rock for Lead, Is one of the oldest rock
Archaeological Significance
Monuments
Used
Not Yet Used
Famous Monuments
Data Not Available
Not Applicable
Sculpture
Not Yet Used
Not Yet Used
Famous Sculptures
Not Applicable
Not Applicable
Pictographs
Not Used
Used
Petroglyphs
Not Used
Used
Figurines
Not Yet Used
Not Yet Used
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.
Dacitic magma is formed by the subduction of young oceanic crust under a thick felsic continental plate. Further, the Oceanic crust is hydrothermally altered as quartz and sodium are added.
Mineral Content
Quartz, Silicon
Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon
Compound Content
Silicon Dioxide
Ca, Fe, Potassium Oxide, Mg, Potassium, Silicon Dioxide
Types of Metamorphism
Not Applicable
Burial Metamorphism, Cataclastic Metamorphism
Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion
Grain Size
Very fine-grained
Medium to Fine Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
Conchoidal
Porosity
Highly Porous
Less Porous
Luster
Waxy and Dull
Subvitreous to Dull
Compressive Strength
Not Available
Cleavage
Non-Existent
Perfect
Toughness
1.5
Not Available
Specific Gravity
2.5-2.8
2.86-2.87
Transparency
Translucent to Opaque
Translucent
Density
2.7 g/cm3
2.77-2.771 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
Not Yet Found
Africa
Kenya, Morocco, South Africa, Tanzania
Not Yet Found
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
France, Greece, Romania, Scotland, Spain
Others
Greenland, Mid-Atlantic Ridge
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
USA
South America
Bolivia, Brazil
Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
New Zealand, South Australia, Western Australia
Chert vs Dacite 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 Dacite characteristics assist us to distinguish and recognize rocks. Also you can check about Properties of Chert and Properties of Dacite. Learn more about Chert vs Dacite in the next section. The interior uses of Chert include Decorative aggregates and Homes whereas the interior uses of Dacite include Decorative aggregates, Entryways and Interior decoration. Due to some exceptional properties of Chert and Dacite, 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 Dacite include As dimension stone, Construction aggregate, For road aggregate, Landscaping.
More about Chert and Dacite
Here you can know more about Chert and Dacite. The life cycle of a rock consists of formation of rock, composition of rock and transformation of rock. The composition of Chert and Dacite consists of mineral content and compound content. The mineral content of Chert includes Quartz, Silicon and mineral content of Dacite includes Amphibole, Apatite, Biotite, Feldspar, Garnet, Hornblade, Magnetite, Plagioclase, Pyroxene, Quartz, Zircon. You can also check out the list of all Sedimentary Rocks. When we have to compare Chert vs Dacite, 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, Dacite is available in bluish - grey, brown, grey, light to dark grey colors. Appearance of Chert is Glassy or Pearly and that of Dacite is Vesicular. Properties of rock is another aspect for Chert vs Dacite. The hardness of Chert is 6.5-7 and that of Dacite is 2-2.25. The types of Chert are Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter whereas types of Dacite are Footwall Dacite, Hanging wall Dacite, Tuff and Biotite Dacite. Streak of rock is the color of powder produced when it is dragged across an unweathered surface. The streak of Chert and Dacite is white. The specific heat capacity of Chert is 0.74 kJ/Kg K and that of Dacite 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 Dacite is heat resistant, impact resistant, pressure resistant, wear resistant.