Definition
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Troctolite is a mafic intrusive rock type. It consists essentially of major but variable amounts of olivine and calcic plagioclase along with minor pyroxene. It is an olivine-rich anorthosite, or a pyroxene-depleted relative of gabbro
Discoverer
Unknown
Christian Leopold von Buch
Etymology
from French néphéline, from Greek nephelē
From German Troklotit, from Greek trōktēs, a marine fish (taken to be trout)
Class
Igneous 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
Aphanitic
Phaneritic
Color
Black, Brown, Green, Grey, White
Dark Grey to Black
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Skeletal
Veined and Shiny
Interior Uses
Decorative Aggregates, Homes, Interior Decoration
Bathrooms, Countertops, Decorative Aggregates, Entryways, Flooring, Homes, Interior Decoration, Kitchens
Exterior Uses
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
As Building Stone, As Facing Stone, Garden Decoration, Office Buildings, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture, Small Figurines
Artifacts, Jewellery, Monuments, Sculpture
Commercial Uses
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Types
Peralkaline Nephelinite
Ultramafic rock
Features
Host Rock for Lead
Smooth to touch
Archaeological Significance
Formation
Nephelinite 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.
Troctolite 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
Clinopyroxene, Nepheline, Plagioclase
Augite, Olivine, Plagioclase, Pyroxene
Compound Content
Ca, CaO, Carbon, Cl, MgO
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Types of Metamorphism
Contact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Types of Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Water Erosion
Grain Size
Fine Grained
Coarse Grained
Porosity
Less Porous
Highly Porous
Luster
Vitreous to Metallic
-
Specific Gravity
2.4-2.9
2.86-2.87
Transparency
Opaque
Opaque
Density
2.5-3 g/cm3
2.7-3.3 g/cm3
Resistance
Heat Resistant
Impact Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Africa
Rwanda, Tanzania
South Africa
Europe
-
Germany, Greece, Italy, Scotland, Turkey
Others
Hawaii Islands
Greenland
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Colombia
Brazil, Colombia, Venezuela
Deposits in Oceania Continent
Australia
-
New Zealand, Queensland
All about Nephelinite and Troctolite Properties
Know all about Nephelinite and Troctolite properties here. All properties of rocks are important as they define the type of rock and its application. Nephelinite and Troctolite belong to Igneous Rocks.Texture of Nephelinite is Aphanitic whereas that of Troctolite is Phaneritic. Nephelinite appears Skeletal and Troctolite appears Veined and Shiny. The luster of Nephelinite is vitreous to metallic while that of Troctolite is . Nephelinite is available in black, brown, green, grey, white colors whereas Troctolite is available in dark grey to black colors. The commercial uses of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo) and that of Troctolite are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones.