Definition
Lamprophyre is uncommon igneous rocks primarily occurring as dikes, lopoliths, laccoliths, stocks and small intrusions
Variolites are a group of dark green basic igneous rocks which exhibit pale colored spots, or spherules, especially on weathered surfaces, that give them a pockmarked appearance
History
Origin
-
France
Discoverer
Unknown
Unknown
Etymology
From Greek lampros bright and shining + porphureos purple
From Latin varius, speckled, variegated
Class
Igneous Rocks
Igneous Rocks
Sub-Class
Durable Rock, Medium Hardness Rock
Durable Rock, Hard Rock
Family
Group
Plutonic
Volcanic
Other Categories
Coarse Grained Rock, Fine Grained Rock, Opaque Rock
Opaque Rock
Texture
Porphyritic
Glassy, Massive, Porphyritic, Scoriaceous, Vesicular
Color
Black, Bluish - Grey, Brown, Dark Greenish - Grey, Green, Grey
Black, Brown, Light to Dark Grey
Maintenance
Less
Less
Durability
Durable
Durable
Water Resistant
✔
✘
✔
✘
Scratch Resistant
✔
✘
✔
✘
Stain Resistant
✔
✘
✔
✘
Wind Resistant
✔
✘
✔
✘
Acid Resistant
✔
✘
✔
✘
Appearance
Dull, Banded and Foilated
Dull and Soft
Architecture
Interior Uses
Decorative Aggregates, Interior Decoration
Floor Tiles, Flooring, Homes, Hotels, Kitchens
Exterior Uses
As Building Stone, Office Buildings
Garden Decoration, Office Buildings
Other Architectural Uses
Curbing
Curbing
Industry
Construction Industry
As Dimension Stone, Cement Manufacture, for Road Aggregate, Making natural cement, Manufacture of Magnesium and Dolomite Refractories
As Dimension Stone, Cobblestones, Rail Track Ballast, Roadstone
Medical Industry
Taken as a Supplement for Calcium or Magnesium
-
Antiquity Uses
Artifacts, Monuments, Sculpture
Artifacts, Monuments, Sculpture
Other Uses
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, Creating Artwork
Types
Minette, Alnoite, Camptonite, Monchiquite, Fourchite, Vogesite, Appinite and Spessartite
Metamorphic rock
Features
Always found as volcanic pipes over deep continental crust, Host rock for Diamond, Is one of the oldest rock, Surfaces are often shiny
Has High structural resistance against erosion and climate, Very fine grained rock
Archaeological Significance
Monuments
-
-
Famous Monuments
-
-
Sculpture
-
-
Famous Sculptures
-
-
Pictographs
-
-
Petroglyphs
-
-
Figurines
-
-
Fossils
Absent
Absent
Formation
Lamprophyre formation takes place deep beneath the Earth’s surface at around 150 to 450 kilometres, and are erupted rapidly and violently.
Variolites are a group of dark green basic igneous rocks that exhibit pale colored spots on weathered surfaces that give them a pockmarked appearance.
Composition
Mineral Content
Amphibole, Carbonate, Garnet, Micas, Olivine, Phlogopite, Pyroxene
Olivine, Plagioclase, Pyroxene
Compound Content
Aluminium Oxide, NaCl, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Silicon Dioxide, Titanium Dioxide
Aluminium Oxide, CaO, Iron(III) Oxide, FeO, Potassium Oxide, MgO, MnO, Sodium Oxide, Phosphorus Pentoxide, Silicon Dioxide, Titanium Dioxide
Transformation
Metamorphism
✔
✘
✔
✘
Types of Metamorphism
Cataclastic Metamorphism, Impact Metamorphism
Burial Metamorphism, Cataclastic Metamorphism, Contact Metamorphism, Hydrothermal Metamorphism, Impact Metamorphism, Regional Metamorphism
Weathering
✔
✘
✔
✘
Types of Weathering
Biological Weathering
Biological Weathering, Chemical Weathering, Mechanical Weathering
Erosion
✔
✘
✔
✘
Types of Erosion
Chemical Erosion, Water Erosion, Wind Erosion
-
Physical Properties
Hardness
5-66
1
7
👆🏻
Grain Size
Fine to Coarse Grained
-
Fracture
Conchoidal
Conchoidal
Streak
White
White to Grey
Porosity
Very Less Porous
Less Porous
Luster
Subvitreous to Dull
-
Compressive Strength
120.00 N/mm237.50 N/mm2
0.15
450
👆🏻
Cleavage
Conchoidal
-
Toughness
-
2.3
Specific Gravity
2.86-2.872.8-3
0
8.4
👆🏻
Transparency
Translucent to Opaque
Opaque
Density
2.95-2.96 g/cm32.9-3.1 g/cm3
0
1400
👆🏻
Thermal Properties
Specific Heat Capacity
0.84 kJ/Kg K0.84 kJ/Kg K
0.14
3.2
👆🏻
Resistance
Heat Resistant, Impact Resistant
Heat Resistant, Pressure Resistant, Wear Resistant
Deposits in Eastern Continents
Asia
Russia
India, Russia
Africa
Angola, Botswana, Cameroon, Ethiopia, South Africa
South Africa
Europe
England, Hungary, Iceland, United Kingdom
Iceland
Others
Antarctica, Greenland
-
Deposits in Western Continents
North America
Canada, Mexico, USA
Canada, USA
South America
Argentina, Colombia, Ecuador
Brazil
Deposits in Oceania Continent
Australia
New South Wales, New Zealand, Queensland, South Australia, Western Australia
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