Definition
Lamprophyre is uncommon igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks
Discoverer
Unknown
Unknown
Etymology
From Greek lampros bright and shining + porphureos purple
From the Middle High German verb gneist (to spark; so called because the rock glitters)
Class
Igneous Rocks
Metamorphic Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Group
Plutonic
Not Applicable
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Coarse Grained Rock, Medium Grained Rock, Opaque Rock
Texture
Porphyritic
Banded, Foliated, Platy
Color
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Black, Brown, Pink, Red, White
Durability
Durable
Durable
Scratch Resistant
Yes
Yes
Appearance
Dull, Banded and Foilated
Foliated
Interior Uses
Decorative Aggregates, Interior Decoration
Countertops, Decorative Aggregates, Flooring, Interior Decoration
Exterior Uses
As Building Stone, Office Buildings
As Building Stone, As Facing Stone, Garden Decoration, Paving Stone
Other Architectural Uses
Curbing
Curbing
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone
Medical Industry
Taken as a Supplement for Calcium or Magnesium
Not Yet Used
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts
Commercial Uses
An Oil and Gas Reservoir, As a Feed Additive for Livestock, Gemstone, Metallurgical Flux, Production of Lime, Soil Conditioner, Source of Magnesia (MgO)
Cemetery Markers, Jewelry, Tombstones, Used in aquariums
Types
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite
Augen Gneiss, Henderson Gneiss, Lewisian Gneiss, Archean and Proterozoic Gneiss.
Features
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny
Generally rough to touch, Is one of the oldest rock
Archaeological Significance
Famous Monuments
Data Not Available
Konark Sun Temple in India, Washington Monument, US
Sculpture
Used
Not Yet Used
Famous Sculptures
Data Not Available
Not Applicable
Pictographs
Used
Not Used
Petroglyphs
Used
Not Used
Figurines
Used
Not Yet Used
Formation
Lamprophyre formation takes place deep beneath the Earth’s surface at around 150 to 450 kilometres, and are erupted rapidly and violently.
Gneiss is a high grade metamorphic rock i.e. it has been subjected to higher temperatures and pressures than schist. It is formed by the metamorphosis of Gneiss forms from volcanic rock, shale or granitie.
Mineral Content
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
Biotite, Chlorite, Feldspar, Garnet, Graphite, Hornblade, Micas, Muscovite or Illite, Quartz, Quartzite, Silica, Zircon
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, Magnesium Carbonate, MgO, MnO, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Types of Metamorphism
Cataclastic Metamorphism, Impact Metamorphism
Impact Metamorphism
Types of Weathering
Biological Weathering
Biological Weathering, Mechanical Weathering
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
Chemical Erosion, Coastal Erosion, Sea Erosion
Grain Size
Fine to Coarse Grained
Medium to Coarse Grained
Fracture
Conchoidal
Irregular
Porosity
Very Less Porous
Very Less Porous
Luster
Subvitreous to Dull
Dull
Compressive Strength
Not Available
Toughness
Not Available
1.2
Specific Gravity
2.86-2.87
2.5-2.7
Transparency
Translucent to Opaque
Translucent to Opaque
Density
2.95-2.96 g/cm3
2.6-2.9 g/cm3
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Scratch Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
China, India, Iran, Iraq, Kazakhstan, Kyrgyzstan, Mongolia, Russia
Africa
Angola, Botswana, Cameroon, Ethiopia, South Africa
Cameroon, Ethiopia, Ghana, Kenya, Madagascar, Morocco, Mozambique, Namibia, Nigeria, Tanzania, Togo
Europe
England, Hungary, Iceland, United Kingdom
Albania, Austria, Bosnia and Herzegovina, Finland, France, Georgia, Germany, Hungary, Italy, Kosovo, Monaco, Norway, Poland, Romania, Serbia, Slovakia, Slovenia, Switzerland, Ukraine, United Kingdom
Others
Antarctica, Greenland
Not Yet Found
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, Costa Rica, Cuba, Mexico, Panama, USA
South America
Argentina, Colombia, Ecuador
Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Peru, Venezuela
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, South Australia, Western Australia
New South Wales, New Zealand, Queensland, Victoria