Definition
Gabbro is an intrusive igneous rock which is chemically equivalent to plutonic Basalt
Nephelinite is a fine-grained or aphanitic igneous rock made up almost entirely of nepheline and clinopyroxene (variety augite).
Discoverer
Christian Leopold von Buch
Unknown
Etymology
From Latin glaber bare, smooth, bald
from French néphéline, from Greek nephelē
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Hard Rock
Durable Rock, Hard Rock
Other Categories
Coarse Grained Rock, Opaque Rock
Fine Grained Rock, Opaque Rock
Texture
Phaneritic
Aphanitic
Color
Dark Grey to Black
Black, Brown, Green, Grey, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Veined and Shiny
Skeletal
Interior Uses
Countertops, Decorative Aggregates, Homes, Interior Decoration
Decorative Aggregates, Homes, Interior Decoration
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, Building houses or walls, Cement Manufacture, Construction Aggregate, for Road Aggregate
As Dimension Stone, Cement Manufacture, Construction Aggregate, for Road Aggregate
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture, Small Figurines
Commercial Uses
Cemetery Markers, Commemorative Tablets, Laboratory bench tops, Jewelry, Sea Defence, Tombstones
Creating Artwork, Soil Conditioner, Source of Magnesia (MgO)
Types
Anorthosite Gabbro and Norite Gabbro
Peralkaline Nephelinite
Features
Smooth to touch
Host Rock for Lead
Archaeological Significance
Formation
Gabbro, a mafic rock, forms due to cooling and crystallization of magma underneath Earth's surface.
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.
Mineral Content
Augite, Olivine, Plagioclase, Pyroxene
Clinopyroxene, Nepheline, Plagioclase
Compound Content
Aluminium Oxide, CaO, Chromium(III) Oxide, Iron(III) Oxide, Potassium Oxide, MgO, Sodium Oxide, Silicon Dioxide, Sulfur Trioxide
Ca, CaO, Carbon, Cl, MgO
Types of Metamorphism
Impact Metamorphism
Contact Metamorphism
Types of Weathering
Chemical Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Types of Erosion
Coastal Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Grain Size
Coarse Grained
Fine Grained
Porosity
Highly Porous
Less Porous
Luster
-
Vitreous to Metallic
Specific Gravity
2.86-2.87
2.4-2.9
Transparency
Opaque
Opaque
Density
2.7-3.3 g/cm3
2.5-3 g/cm3
Resistance
Impact Resistant, Pressure Resistant, Wear Resistant
Heat Resistant
Deposits in Eastern Continents
Africa
South Africa
Rwanda, Tanzania
Europe
Germany, Greece, Italy, Scotland, Turkey
-
Others
Greenland
Hawaii Islands
Deposits in Western Continents
North America
Canada, USA
Canada, USA
South America
Brazil, Colombia, Venezuela
Colombia
Deposits in Oceania Continent
Australia
New Zealand, Queensland
-
All about Gabbro and Nephelinite Properties
Know all about Gabbro and Nephelinite properties here. All properties of rocks are important as they define the type of rock and its application. Gabbro and Nephelinite belong to Igneous Rocks.Texture of Gabbro is Phaneritic whereas that of Nephelinite is Aphanitic. Gabbro appears Veined and Shiny and Nephelinite appears Skeletal. The luster of Gabbro is while that of Nephelinite is vitreous to metallic. Gabbro is available in dark grey to black colors whereas Nephelinite is available in black, brown, green, grey, white colors. The commercial uses of Gabbro are cemetery markers, commemorative tablets, laboratory bench tops, jewelry, sea defence, tombstones and that of Nephelinite are creating artwork, soil conditioner, source of magnesia (mgo).