1 Definition
1.1 Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Trachyte is a grey fine-grained volcanic rock which mainly consists of alkali feldspar
1.2 History
1.2.1 Origin
1.2.2 Discoverer
Unknown
Alexandre Brongniart and René Just Haüy
1.3 Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From Greek trakhus rough’ or trakhutēs roughness
1.4 Class
Sedimentary Rocks
Igneous Rocks
1.4.1 Sub-Class
Durable Rock, Hard Rock
Durable Rock, Medium Hardness Rock
1.5 Family
1.5.1 Group
1.6 Other Categories
Fine Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
2 Texture
2.1 Texture
Banded, Rough
Aphanitic to Porphyritic
2.2 Color
Black, Brown, Green, Grey, Red, White
Black, Brown, Dark Greenish - Grey, Green, Grey, Light to Dark Grey, White
2.3 Maintenance
2.4 Durability
2.4.1 Water Resistant
2.4.2 Scratch Resistant
2.4.3 Stain Resistant
2.4.4 Wind Resistant
2.4.5 Acid Resistant
2.5 Appearance
3 Uses
3.1 Architecture
3.1.1 Interior Uses
Decorative Aggregates, Homes
Decorative Aggregates, Flooring, Homes, Interior Decoration
3.1.2 Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
3.1.3 Other Architectural Uses
3.2 Industry
3.2.1 Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate, Landscaping, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
3.2.2 Medical Industry
Not Yet Used
Not Yet Used
3.3 Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture, Small Figurines
3.4 Other Uses
3.4.1 Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Cemetery Markers, Creating Artwork
4 Types
4.1 Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Not Available
4.2 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, Is one of the oldest rock, Matrix variable
4.3 Archaeological Significance
4.3.1 Monuments
4.3.2 Famous Monuments
Data Not Available
Data Not Available
4.3.3 Sculpture
4.3.4 Famous Sculptures
Not Applicable
Data Not Available
4.3.5 Pictographs
4.3.6 Petroglyphs
4.3.7 Figurines
4.4 Fossils
5 Formation
5.1 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.
Trachyte is an igneous volcanic rock with an aphanitic to porphyritic texture. It is the volcanic equivalent of syenite rock and forms as a result of magmatic differentiation.
5.2 Composition
5.2.1 Mineral Content
Quartz, Silicon
Augite, Biotite, Feldspar, Hornblade, Plagioclase, Quartz
5.2.2 Compound Content
Silicon Dioxide
Potassium Oxide, Sodium Oxide, Silicon Dioxide
5.3 Transformation
5.3.1 Metamorphism
5.3.2 Types of Metamorphism
Not Applicable
Cataclastic Metamorphism, Contact Metamorphism, Regional Metamorphism
5.3.3 Weathering
5.3.4 Types of Weathering
Not Applicable
Biological Weathering, Chemical Weathering, Mechanical Weathering
5.3.5 Erosion
5.3.6 Types of Erosion
Chemical Erosion
Chemical Erosion, Coastal Erosion, Glacier Erosion, Sea Erosion, Water Erosion, Wind Erosion
6 Properties
6.1 Physical Properties
6.1.1 Hardness
6.1.2 Grain Size
Very fine-grained
Fine Grained
6.1.3 Fracture
Uneven, Splintery or Conchoidal
Not Available
6.1.4 Streak
6.1.5 Porosity
Highly Porous
Less Porous
6.1.6 Luster
6.1.7 Compressive Strength
450.00 N/mm2150.00 N/mm2
0.15
450
6.1.8 Cleavage
Non-Existent
Not Available
6.1.9 Toughness
6.1.10 Specific Gravity
2.4.1 Transparency
Translucent to Opaque
Opaque
2.4.3 Density
2.7 g/cm32.43-2.45 g/cm3
0
1400
4.4 Thermal Properties
4.4.1 Specific Heat Capacity
1.6.1 Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant, Wear Resistant
2 Reserves
2.1 Deposits in Eastern Continents
2.1.1 Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
3.1.1 Africa
Kenya, Morocco, South Africa, Tanzania
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
3.1.2 Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Bulgaria, England, Germany, Norway, Romania, Switzerland
3.1.3 Others
Greenland, Mid-Atlantic Ridge
Not Yet Found
3.3 Deposits in Western Continents
3.3.1 North America
3.3.2 South America
Bolivia, Brazil
Brazil, Chile
3.5 Deposits in Oceania Continent
3.5.1 Australia
New South Wales, Queensland, South Australia, Western Australia
New Zealand, Queensland, South Australia, Western Australia