Definition
Norite is a mafic intrusive igneous rock composed largely of the calcium-rich plagioclase labradorite, orthopyroxene, and olivine
Argillites are highly compact sedimentary or slightly metamorphosed rocks that consist largely or wholly of particles of clay or silt but lack the fissility of shale or the cleavage characteristic of slate
Discoverer
Unknown
Unknown
Etymology
From the Norwegian name for Norway, Norge
From Latin Argilla (clay) and -ite in English which became agrilla+ -ite = Argillite
Class
Igneous Rocks
Sedimentary Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Soft Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phaneritic
Clastic, Polished
Color
Dark Grey to Black
Dark Grey to Black, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined and Shiny
Rough and Dull
Interior Uses
Decorative Aggregates, Entryways, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
Exterior Uses
As Building Stone, As Facing Stone, Paving Stone, Garden Decoration
As Building Stone, Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing, Whetstones
Construction Industry
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Used for flooring, stair treads, borders and window sills.
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Commercial Uses
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Fire resistant, Used to manufracture paperweights and bookends
Types
Ultramafic intrusive rock
Metamorphic rock
Features
Smooth to touch
Is one of the oldest rock
Archaeological Significance
Formation
Norite 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.
An argillite is a fine-grained sedimentary rock mainly composed of clay particles which forms from lithified muds which contain variable amounts of silt-sized particles.
Mineral Content
Augite, Olivine, Plagioclase, Pyroxene
Biotite, Chlorite, Feldspar, Micas, Muscovite or Illite, Plagioclase, Pyrite, Quartz
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Iron(III) Oxide, Potassium Oxide, MgO, Silicon Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Impact Metamorphism
-
Types of Weathering
Biological Weathering
Biological Weathering
Types of Erosion
Chemical Erosion, Coastal Erosion
Chemical Erosion
Grain Size
Coarse Grained
Fine Grained
Fracture
Conchoidal
Conchoidal to Uneven
Streak
Black
White to Grey
Porosity
Highly Porous
Highly Porous
Specific Gravity
2.86-2.87
2.56-2.68
Transparency
Opaque
Opaque
Density
2.7-3.3 g/cm3
2.54-2.66 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant, Impact Resistant
Deposits in Eastern Continents
Asia
India, Russia
Bangladesh, China, India, Russia
Africa
South Africa
Ethiopia, Kenya, Morocco, South Africa, Tanzania
Europe
Germany, Greece, Italy, Scotland, Turkey
Austria, France, Germany, Greece, Italy, Romania, Scotland, Spain, Switzerland
Deposits in Western Continents
North America
Canada, USA
USA
South America
Brazil, Colombia, Venezuela
Bolivia, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New Zealand, Queensland
New South Wales, New Zealand, Queensland, Victoria, Western Australia