Definition
Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture
Luxullianite is a rare type of granite, known for presence of clusters of radially arranged acicular tourmaline crystals which are enclosed by phenocrysts of orthoclase and quartz in a matrix of quartz, tourmaline, alkali feldspar, brown mica.
Discoverer
Unknown
Unknown
Etymology
From flint-like quartz, 1670s, of unknown origin- a local term, which has been taken into geological use
From the village of Luxulyan in Cornwall, England, where this variety of granite is found
Class
Sedimentary Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Opaque Rock
Texture
Banded, Rough
Granular, Phaneritic
Color
Black, Brown, Green, Grey, Red, White
Black, Grey, Orange, Pink, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Glassy or Pearly
Veined or Pebbled
Interior Uses
Decorative Aggregates, Homes
Bathrooms, Countertops, Decorative Aggregates, Entryways, Floor Tiles, Homes, Hotels, Interior Decoration, Kitchens, Stair Treads
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Construction Industry
Arrowheads, Construction Aggregate, Cutting Tool, Spear Points
As Dimension Stone
Antiquity Uses
Artifacts, Monuments
Artifacts, Monuments, Sculpture
Commercial Uses
Creating Artwork, Gemstone, In fire-starting tools, Jewelry, To ignite fire, Used in flintlock firearms
Creating Artwork, Curling, Gemstone, Laboratory bench tops, Tombstones
Types
Flint, Jasper, Radiolarite, Common Chert, Chalcedony, Agate, Onyx, Opal, Magadi-type Chert, Porcelanite, Siliceous Sinter
Igneous Protolith Granite, Sedimentary Protolith Granite, Mantle Granite, Anorogenic Granite and Hybrid Granite
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, It is One of the Oldest, Strongest and Hardest 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.
Luxullianite is an intrusive igneous rock which is very hard, crystalline and is visibly homogeneous in texture. It is found in large plutons on the continents, i.e. in areas where the Earth's crust has been deeply eroded.
Mineral Content
Quartz, Silicon
Amphibole, Biotite, Feldspar, Hornblade, Micas, Muscovite or Illite, Plagioclase, Pyroxene, Quartz
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, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism
Types of Weathering
-
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Very fine-grained
Large and Coarse Grained
Fracture
Uneven, Splintery or Conchoidal
-
Porosity
Highly Porous
Less Porous
Luster
Waxy and Dull
Dull to Grainy with Sporadic parts Pearly and Vitreous
Specific Gravity
2.5-2.8
2.6-2.7
Transparency
Translucent to Opaque
Opaque
Density
2.7 g/cm3
2.6-2.8 g/cm3
Resistance
Heat Resistant, Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
China, India, Iran, Japan, Oman, Russia, Saudi Arabia, Taiwan, Thailand, Vietnam
China, India, Iran, Saudi Arabia, Sri Lanka, Taiwan, Thailand, Turkey, Vietnam
Africa
Kenya, Morocco, South Africa, Tanzania
Angola, Egypt, Madagascar, Namibia, Nigeria, South Africa
Europe
Austria, France, Greece, Italy, Malta, Poland, Portugal, Serbia, Spain, Sweden, United Kingdom
Austria, Belgium, Finland, France, Germany, Italy, Norway, Sardinia, Spain, Switzerland, The Czech Republic
Others
Greenland, Mid-Atlantic Ridge
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Bolivia, Brazil
-
Deposits in Oceania Continent
Australia
New South Wales, Queensland, South Australia, Western Australia
-
All about Chert and Luxullianite Properties
Know all about Chert and Luxullianite properties here. All properties of rocks are important as they define the type of rock and its application. Chert belongs to Sedimentary Rocks while Luxullianite belongs to Igneous Rocks.Texture of Chert is Banded, Rough whereas that of Luxullianite is Granular, Phaneritic. Chert appears Glassy or Pearly and Luxullianite appears Veined or Pebbled. The luster of Chert is waxy and dull while that of Luxullianite is dull to grainy with sporadic parts pearly and vitreous. Chert is available in black, brown, green, grey, red, white colors whereas Luxullianite is available in black, grey, orange, pink, white colors. The commercial uses of Chert are creating artwork, gemstone, in fire-starting tools, jewelry, to ignite fire, used in flintlock firearms and that of Luxullianite are creating artwork, curling, gemstone, laboratory bench tops, tombstones.